ML20079L150

Provides Suppl Info on Programmable Logic Controllers for Station Blackout/Electrical Safeguards Upgrade Project

ML20079L150
Person / Time
Site:	Prairie Island
Issue date:	10/24/1991
From:	Parker T NORTHERN STATES POWER CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
TAC-M68588, TAC-M68589, NUDOCS 9111060118
Download: ML20079L150 (15)

Text

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Northem States Power Company 414 Nicollet Mall Minneapohs Minnesota 55401 1927 Telephone (612) 330-5500 October 24, 1991 10 CFR 50.63(c)(d)

U S Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555 PRAIRIE ISLAND NUCLEAR GENERATING PLANT Docket Nos. 50 282 License Nos. DPR-42 50 306 DPR 60 Supplemental Information on Programmable Logic Controllers for the Station Blackout / Electrical Safeguards Upgrade Project (TAC Nos lh8588 andT68589)

References:

1) Letter from Thomas M Parker, Northern States Power Company, to U S Nuclear Regulatory Commission dated November 27, 1990 titled " Design Report for the Station Blackout / Electrical Safeguards Upgrade Project"

2) Letter from Armando Masciantonio, U S Nuclear Regulatory Commission, dated June 6, 1991 titled " Request for Additional Information Station Blackout / Electrical Safeguards Upgrade Project (TAC Nos. 68588/68589)

On November 27, 1990 we submitted for NRC Staff review the design report (Reference 1) for our project to add two additional safeguards emergency diesel denerators, to upgrade the safeguards electrical distribution system, and to upgrade #121 Cooling Uater Pump to become a swing safeguards pump.

On June 6, 1991 the-NRC Staff requested additional information (Reference 2) regarding the load sequencers and the programmable logic controllers that comprise the load sequencers. We provided the information requested in a letter dated July 10, 1991, llowever, we also will utilize programmable logic controllers in the new 480VAC voltage regulators. Following discussion with the NRR project manager for Prairic Island, Armand Masciantonio, we agreed to respond to the same questions as applicable to the voltage regulator programmable logic controllers. Our response is attached to this letter.

In the attached response, we quote the 15 questions but replace the words

" load sequencer" with " voltage regulator" wherever they appear.

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l Northern States Power Company Please contact us-if you have any questions related to the responses to the questions.

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Thomas M Parker Manager Nuclear Support Services c: Regional t.dministrator - Region III, NRC Senior Resident Inspector, NRC NRR Project Manager, NRC J E Silberg Attachments:

1. - Response to Request for Additional Information l

2. Voltage Regulator Programmable Controller Processor Specifications (7 Pages) e

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ATTAC11 MENT 1 EQRTHERN STATES . POWER COMPANY f ERAIRIE ISLAND NUCLEAR GENERATING PIANT [

STATION BLACKOUT / ELECTRICAL SAFEGUARDS UPGRADE PROJECT  ;

RESPONSE TO RE0QEST FVR ADDITIONAL INFVRMATION - l

References:

1.  !"D::1 6n Report for the Station Blackout / Electrical Safeguards Upgrade i

_ Proj ec t" . Northern States Power Company, November 27, 1990.

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2. ANS1/IEEE ANS-7-4.3,2 1982, "American Nationt.1 Standard. Application Criteria for Programmable Digital Computer Systems in Safety Systems of '

Nuclear Generating Stations".

OUESTION 1:

Provide the design information of the (Unit 1 &] Unit 2 [voltago .;

. regulator] programmable logic controller (PLC) (i.e., manufacturer, model

• number, etc.). Include in the description of the devices used in the (voltage regulators), the [ voltage regulator] PLC programming language, xcompiler, type of microprocessors, etc.

- RESPONSE TO OUESTION If The voltage regulator uses an Allen Bradicy 1747-L511 SLC 500 Programmable Control 5.er as the main processor. The programmable logic controller is I

provided with an EEPROM memory _ module for non volatile storage of the application programs. Additional components of the voltage regulator programmable logic controller include:

1746-P1 _ Power Supply _ _ _

1746-IA8 120 VAC 8 Point Input Module 1746-0W16 16 Point Relay Output Module >

1746-0B8 8 Point Transistor.Sourcing Module 1746-N14- 4 Point Analog Input l~ -Applicable product specification sheets are provided as Attachmont'2 to this-submittal, j;

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The Allen Bradley programmabic logic controller was programmed using:

I' l Allen-Bradley SLC-500-Advanced Programming Software

1. 1747 PAZE,_ Revision 2.01 b This program is a_ tool to program the_ processor with tha system ladder-logic.

The appropriate programmable logic-controller commands are enteredfinto'the system as rungs of a ladder. This ladder logic format la read by the programmable logic controller and interpreted into programwable logie controller commands.-

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Attachment 1 october 21, 1991 Page 2 of 6 OUEST10N 2:

NRC Regulatory Culde 1.152, which endorses ANSI /IEEE-ANS 7-4.3.2-1982 (Ref. 2), is not -referenced in the Northern States Power Company (NSPC)

. submittal (Ref, 1), Provide documentation of the acceptance criteria for the (voltage regulator] system, and justify differences between the NSPC acceptance criteria and the Ref. 2 criteria.

Describe the plans for performing or reviewing the verification and validation (V&V) of the programmable logic controller (PLC) [ voltage regulator] logio to be implemented on [ Unit 1 6) Unit 2. If the V&V has .

been performed, provide the documentacion of the V&V plan. If a V6V plan has not been developed, describe the process by which NSP will ensure the adequacy of the PLCs for 1E applications.

RESPONSE TO OUESTION.2:

The voltage regulator programmable logic controller system verification &

validation (V&V) plan has been implemented in accordance with ANSI /IEEE-ANS-7 4.3.2-1982. A final V&V Report will be submitted to NSP which will summarize the results of the system validation testing and will show how the system is in compliance with the original system requirements.

QUESTION 3:

Lescribe the acceptance criteria for checking control cabinet instruments and control logic.

RESPONSE TO OUESIl0N 3:

The control cabinet instruments and control logic functions were fully tested during the V6V testing phases. This included module testing and integrated testing. The controlling function of th+ voltage regulator was verified.by

. varying the input. voltage between 310 VAC and 620 VAC and insuring that the output voltage remained within its desired range.

QUESTION 4:

Describe site acceptance /preoperational testing; specifically address loss and restoration of power to the PLCs during standby and power operation.

Also describe the memory-retention capability of the PLC.

j RESPONSE TO OUESTION 4:

l l Site acceptance' testing of the voltage regulators will demonstrate that the system will respond correctly during varied input voltage conditions. The programmable' logic controller logic will be functionally tested during the integrated preoperational testing of the new emergency diesel generators.

Upon loss of power to the programmable logic controller, an EEPROM memory

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At t achmerit 1 Octnber 21, 1991 Page 3 of 6  !

module installed in the programmable logic controller'will contain a copy of the operating program which can be downloaded to the programmable logic  !

controller memory on every power up sequence, When power is restored to the -

-programmable logic controller, the regulator will resume operation at that point.

OUESTION 5:

Provide the frequency at which the PLC [ voltage regulator] algorithm will be testea, and discuss coordination of this testing with normal voltage regulator operations.

RESPONSE TO OUESTION 5:

Voltage regulator testing will take place during refueling outages and will be coordinated with 4160 VAC bus and 480VAC bus outages. The voltage regulator and.the buses will be out af service during the testing, so that no coordination with normal voltage regulator operations is required.

OUESTION 6:

. Describe the methods by which a loss of [ voltage regulator} function is detected and mitigated, including the steps required to recever the voltage regulator function'.

RESPONSE TO OUESTION 6: ,

The programmable logic controller processor contains a watchdog timer which l will alarm if the programmable logic controller software does not complete a cycle in a-predefined time period. In addition, the programmable logic controller logic will alarm on the loss of AC control power. The voltage

-regulator programmable logic controller is ' reset' by cycling AC power to the programmable logic controller, This action will-perform a restart of the regulator, i

OUESTION 7:

Provide the PLC Surge Withstand Capability (SWC) specifications, and justify the margin between the SWC and expected surges. Include tho PLC power sources.

EESPONSE TO OUESTION 7:

The programmable logic controllers' logic power supply requires a 120VAC externa 11 source of power, This external 120VAC will be supplied from 120VAC uninterruptable power supplies which will provide a regulated and filtered

. source of power to the units.

According to Allen-Bradley : product literature, the SLC-500 family of j: _ programmable logic controllers has been tested for noise immunity in i

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At6schment 1 October 21, 1C91 Page 4 of 6 accordance with NEMA Publication ICS 2 Section ICS-2-230.

OUESTION 8:

Provide the PLC Electromagnetic Compatibility (EMC) specifications, and justify the margin between the EMC specifications and the electromagnetic interference.

RESPONSE TO OUESTION 8:

There are no streng sources of radio frequency interference (RFI) in the vicinity of Prairie Island which are not under plant control (such as commercial radio or television transmitters). A radio frequency interference survey of the control rod drive rooms conducted in 1985 confirmed this when levels less than 100 r,"/ meter were measured. Therefore. the source of objectionable radio frequency interference is primarily from the use of hand held walkie talkies near susceptible solid state equipment.

To ensure that the programmable logic controllers within the voltage regulator are sufficiently immune to the expected electromagnetic interference at tLe Prairie Island site, the equipment will be tested for radiated and conderted susceptibility in accordance with SAMA Standard PMC 33.1-1978, and MIL Standard 461 and MIL Standard 462. MIL Standard Test Methods CS01, Cr02 and CS06 will be the basis for the conducted susceptibility test. The Prairie Island site falls into Class 2 for radiated atsceptibility as defined by SAMA Standard PMC 33.1-1978, since hand held trans.nitters are the primary scurce of objectionable electrouagnetic interference. The equipment will therefo c be tested for a 10 Volt / meter radiated field strength. An electromcgnetic interference survey of the D5/b6 Building will be conducted to confirm this Class 2 field strength designation.

OUESTION 4:

Provide a detailed description of the device (s) used to accoirglish electrical isolation between IE and non-1E systems and describe the specific testing performed to demonstrate that the devices ,re acceptable for this application. Thic description should include elementary diagrams to indicate the test configuration and how the maximum credible faults were applied to the device (s).

RESPONSE TO OUESTION 4:

The only non 1E interface to the voltage rr.gulator is the programmabic logic controller trouble alarm output contact which is connected to the plant computer remote multiplexor unit. This alarm contact signal is generated by an isolated relay contact output f rom the SLC- 500 output module . The same quality class of cable is used for alarm input connection as is used for the safety-related wiring in the plant. This wiring is also routed in control raceways which do not contain any pow?r ('.80VAC or 4160VAC) circuits. The power supply associated with the remote multiplexor unit input is power

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Attochnent 1 October 21, 1991 Page 5 of 6 limited, and cannot d: liver currents in excess of 2 to 3 amperes even with a bolted fault across the power supply output. The remote multtplexor input circuit is also protected with a 1.5 amp fuse which will furthar limit the fault-current, Based on the above, we have concluded that the programmable logic controller trouble alarm output contact is suitably isolated and protected, and no additional. testing is required, Ol'ESTION 10:

Provide data'to verify that the maximum credible faults applied during the

[

test (s) discussed in Question #9 were the maximum voltage / current to which

.the device :could be exposed, and define how the maximum voltage / current was determined.

-RESPONSE TO OUESTION 10:

, A discussion of the maximum credible fault on the non-1E remote multiplexor unit input is contained in our response.to Question 9 above.

QERSTION 11:

Provide data;to verify that the maximum credible fault was applied to the output of the device in the transverse mode (between signal and return) and to verify that other. faults were-considered (i.e., open and short circuits).

RESPONSE TO OUESTION 11:

A programmable logic controller relay type output is used to isolate the non-lE alarm signal. There is no common return path between this alarm output and the other programmable logic outputs, Therefore, there is no tran' verse s mode

-fault mechanism, Short circuits are discussed in-our response to Question 9. Because relay _

outputs are used as isolation devices,-open circuits on the alarm wiring will-

-not affect other programmable logic controller functions.

QUESTION 17:

i Define the pass / fail acceptance criteria for each type of isolation-L- device.

RESPONSE TO-OUESTION 12:

See response to Question 9,

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Attachment 1 October 21, 1991-N Page 6 of 6-OUESTION 13:

Discuss _the process by which NSPC will verify that the electromagnetic environment at the plant-site is enveloped by the PLC manufacturer's EMC test parameters. ,._

RESPONSE TO OUESTION 13:

-As stated in cur response to Question 8, an electromagnetic interference site survey will be conducted, and the results of this survey vill be compared to the electromagnetic interference test intensities to ensure that the test envelopes the measured values. 1 OUESTION 14 Describe the configuration control plan for the [ Unit 1 6] Unit 2 (voltage regulator).

RESP 0MSE TO OUESTION 14:

During the software development and V6V testing phases, the configuration

-control of- the_ programmable logic controller ladder logic and data files is administered by the voltage regulator vendor in accordance with their QA Manual and the. verification and validation plan.

After the' voltage regulator is delivered to NSP, responsibility for configuration control is transferred to 'the Electrical Systems Engf.neering group.at the. plant site. Control of the system will be accomplished in'three areas and in accordance with the Prairie Island Quality Assuranco Manual.

-First, any periodic testing vill be done in accordance with the-Surveillance

. Procedure _ program. Second, any troubleshooting - without_ changing ladder logic or data files - will-be done in accordance with the-Work Control program. Finally, any changes to the hardware or software will be.done-in accordance with the Uniform Modification Process, includi'ag 10CFR50.59 reviews.

CUESTION 15:

i e Provide.the Mean-Time-To-Failure (MTTF) and the_Menn Time-To Repair (MTTR) ,

I L  : information-for-the PLCs.

RESPONSE TO OUESTION 15:

1The Mean-Time-To-Failure:(MTTF) is derived from Allen-Bradicy calculations based on MIL-217D procedures. These calculations yielded an' estimated MTBF range of 20,000 to 40,000 hours0 days <br />0 hours <br />0 weeks <br />0 months <br /> -for- the SLc4500 CPU, power supplies, racks, and I/0. The Mean-Time-To Repair (MTTR) is the time required to replace the l l faulty module and return the voltage regulator to service, but does not _;

include personnel mobilization time. This time to repair is one hour, i I

ATTACllMENT 2 Chapter SpedHeadons i

G Specifications 1

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l CA TALOG NUMett

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DtiCRIPTION gygy43g g gy474gg4 i

Memory Type Caiaotor backed RAM Memory Battery backec RAM stancard i

Bat 'ery Back uo optionai .

Optional tt PROM and OvPROM memory modules avatlable Power Supply Loaomg at 5 volts DC 0 35 Ampere Power supply Leading at 24 volts DC - 0105 Aerre o Caoactor Life Refer to the curve below None j' Sattery Life 5 years 2 years Memory $de 1K instruction Capacity 4K Instruction Capaoty Scan Tiane 10 milliseconds /1K (typical)

Program Scan Hold up Time after toss of Power 20 millisecones to 3 seconds (dependent on power supply loading)

IC Caoacty 256 to pomts- 3 rack . 30 slots Noise immunit/ NtMA5tandardIC5 2 230 Ambient Ternperature Ratmg Operstmg: 0*C to . 60*C Storage: 40*Cto + 45'C I

H umidity 5 to 95 % without concensation l

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i 25 TIME

' 20 **= ,

CAP ACTOR MIMORY TIME V5 TEMPERATURE (DAYS) 15 - -

i 10 - -

L 5_ _

N 25 30 35 40 a5 50 55 60 TEMPERATURt *C I

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Chapter 6 Spumcadons Specifications Power Supplies CATALOG CATALOG CATALOG DESCRIPTION -

1746 P1 1746-P2 1746-P3 Line Voltage 85-132 /170 265 Volu 85-132 /170 265 Volts 19.2 28 8 Volta DC AC 50/60 Hz AC 50/60 Hz Rfouire ent 135VA 180VA 90VA Internal Current Capacity 2 Amperes 5 Amperes 3.6 Amperes at 5 Volts DC at 5 volts DC at 5 Voits DC 0.46 Ampere 0.96 Ampere 0.87 Ampere at 24 Volts DC at 24 Volts DC at 24 Volts DC User Current Capacity 24 Volts DC- 24 Volts DC- .

0.2 Ampere 0.2 Ampere Fuse Protection 3 Amperes 3 Amperes 5 Amperes Ambient Operating 0 to + 55'C Temperature Rating (Current capacity derated by 5% at + 60*C)

Humidity Rating 5-95% (non-condensing)

Wiring # 14 AWG _

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l Chapter 6 Specifications 63 Specifications Input Modules Catalog Poinis Per Type Specifications Number Module

"' 9 1746-IA4 4 Frequency: 47 63 Hz 100/120 Off State Voltage: 30 VAC(maximum) 1746-IAS Volts AC 8 Nominalinput Current: 12mA at 120 VAC

_ Turn-On Time: 35 msec. (maximum) 1746tA16

"'"' *' '"'('"#**"*

16 Maximum Off State Current: 2mA On State Voltage: 170-265 VAC U4MM4 4 Frequency: 47-63 rir 200/240 Off StateVoltage: 50 VAC (max.)

1746-IM8 Volts AC 8 Nominal Input Current: 12mA at 240 VAC Turn On Time: 35 msec. (maximum)

U4MMM Turn-Off Time: 45 msec. (maximum)

M Maximum Off State Current: 2mA 1746-188 8 24 On . Voltage: 10-30 VOC 1746-1816 Volts DC 16 .. ate Voltage: 5 VDC(maximum)

Sink Wominalinput Current: 8 mA at 24 VOC

& Turn-On Time: 8 msec. (maximum) 1746-IV8 Source 8 Turn Off Time: 8 msec. (maximum)

Maximum Off State Current: ImA 1746-IV16 16 l.ow True / Sourcing, Schmitt Trigger User Supplied Voltage: 4.5 to 5.5 VDC.

50 mV p-p ripple maximum On-State Voltage: -0.2 to + 0.8 VDC Off StateVoltage: 2.0 to 5.5 VDC 174$1G16 5 16 User Supplied Current: 175mA marimum at 5 VDC Volts DC Nominalinput Current: 3.7mA Turn On Time: 0.25 msec. (maximum)

Turn Off Time: 0.50 msec. (maximum)

Maximum Off htate Current: 4.1 m A.

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Chapter G Specifications SpecificatlOns Output Modules Catalog Type Points Per Specific.ations Number Module On State Voltage: 80 265 VAC Maximum On-State Voltage Drop:

1746-OA8 1.5 Volts (maximum) at 1 Ampere 1746-OA16 1.5 Volts (maximum) at 0.5 A m oere 1746-OA8 8 Frequency: 47-63 Hz Continuous Current (per output):

1746-OA8 1 Ampere at + 30*C 0.5 Ampere at + 60*C 1746-OA16 0.5 Amp at + 30*C 120/240 0.25 Ampere at + 60*C Volts AC Continuous Current (per module): 8 Amperes at + 30*C ,

Tnac 4 Amperes at + 60*C Minimum Load Current: 10mA Surge Current (per output): 10 Amperes for 25 msec.

recurnng once per second maximum at + 30*C 1746-OA16 16

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returnng once every two seconds maximum at

+ 60*C Turn-On Time: 0.1 msec. (maximum)

Turn Off Time: 11 msec. (maximum)

Maximum Off State Leakage Current: 2mA Output Voltage: 0 50 VDC Maximum On State Voltage Drop: 1.2 Volts maximum at 1 Ampere Continuous Current (per output): 1 Ampere at + 30*C 0 5 Ampere at + 60*C Continuous Current (per module): 8 Amperes at + 30*C 4 Amperes at + 60*C 24 Minimum Load Current: 1mA Volts DC Surge Current (per output): 3 Amperes for 10 msec.

1746-0B8 8 Source recurnng once per second maximum at + 30*C 3 Amperes for 10 msec.

recurnng once every two seconds maximum at

+ 60*C Turn On Time: 0.1 msec. (maximum)

Turn Off Time: 1.0 msec. (maximum)

Maximum Off State Leakage Current: 1mA i

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Chapter 6 Specifications 6-S Specifications Output Modules I

Catalog Points Per Type Specifications Number Module Low True / Sinking, Schmitt Tngger User Supplied Voltage: 4.5 to 5.5 VOC 50mV p p ripple maximum 5 User Supplied Current: 495mA maximum at 5 VOC 1746 OG16 16 Continuous Current (per output):

Volts DC 24mA Minimum Load Current: 0.15mA Turn-On Time: 0.25 msec. (maximum)

Turn-Off Time: 0.50 msec. (maximum)

Maximum Off. State Current: 0.1mA Output Voltage: 10 50 VDC Maximum On-State Voltage Drop:

1746-OV8 1.2 Volts (maximum) at 1 Ampere 1746-OV16 1.2 Volts (maximum) at Continuous Current (per output):

1746-OV8 1 Ampere at + 30*C 0.5 Ampere at + 60*C 24 1746-OV16 0.5 Ampere at + 30*C Volts 0.25 Ampere at + 60*C Sink Continuous Current (per module): 8 Amperes at + 30*C 4 Amperes at + 60*C Minimum Load Current: 1mA Surge Current (per output): 3 Amperes for 10 msec.

recurring once per second maximum at + 30*C 1746-OV16 16 3 Amperes for 10 msec.

recurnng once every two seconos maximum at

?60*C Turn-On Time: 0.1 msec. (maximum)

Turn Off Time: 1.0 msec. (maximum)

Maximum Off State Leakage Current: ImA Output Voltage: 5-265 VAC 5-138 VOC 1746 OW4 4 Continuous Current (per output):

1746 OW4 & 1746-OW8 2.0 Amperes 1746-OW16 1.0 Ampere Turn-On Time: 10 msec. (maximum)

Turn-Off Time: 10 msec. (maximum) 1746-OW8 'Y S Maximum Off-State Leakage Current: OmA (3ee footnote C on Page Maximum Amperes Amperes Voltamperes 6-4) Volts Continuous Make Break Make Break 240VAC 7.5A 0.75A 120VAC 15A 2.0A 1800VA 180VA 1.5 A 1746-OW16 16 125VOC 0.22A 1.0A 28VA 24VOC 1.2A 2.0A 2SVA

Gnapter 6 Specifications 6-2 Catalog No.1746 NI4 Analog input Module

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DESCRIPTION SPECIFICATION GENERAL Input Channels per Module 4 differential, voltage or current selectable per channel, not individually isolated Field Wiring to Backplane isolation 500 Volts DC Backp:ane Power Consumption 25mA at 5 Volts DC 100mA at 24 Volts DC Update Time 512 s. for all channels in parallel

, SLC Communication Format 16 Bit Two's Complement Binary Calibration Factory Calibrated Environmental Conditions Operating Temperature O to + 60*C Storage Temperature 40*C to + 85*C Relative Humidity 5 95% (non-condensing)

Terminal Block Removable Maximum Wire Size #14 AWG Recommended Cable Belden #8761 -

1.ocation 1746 Rack INPUT GENERAL Converter Resolucon 16 Bit t.ocation of LSB in t/O image word 0000 0000 0000 0001

( Non lineanty 0.01 %

Common Mode Voltat, - Range -20 Volts DC to + 20 Volts DC Common Mode Rejection at 0 to 10 Hz (minimum) 50dB Common Mode Rejection at 60 Hz (minimum) 115dB Normal Mode Rejection at 60 Hz (minimum) 55dd Channel Bandwidth 10 Hz Settling Time G 60 milliseconds Conversion Method Delta Sigma Modulation Voltage input Coding ( 10VOC to + 10VOC ILSB) 32768to + 32767 l Current input Coding ( 20mA to + 20mA) 16384 to + 16384

( 30mA to + 30mA) 24576 to . 24576 O Refer to Page 312.

1 l

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Chapter 6 Specifications Catalog No.1746 NI4 Analog Input Module DESCRIPTION SPEOFICATION CURRENT MODE INPUT Full 5cale = 20mA Vcm = 0 Input Range (Normal Operation) -20mA to + 20mA Absolute Maximum input Current t 30mA Absolute Maximum Input Voltage  : 7.5 Volts DC or 7.5 Volts AC RMS Input impedance 250 Ohms Resolution 1.22077pA per LSB Overall Accuracy (at + 25'C maximum) 10.365% of full scale Overall Accuracy (0 to + 60*C maximum) 10.642% of full scale Overall Accuracy Orift(maximum) 179ppmfC of full scale Gain Error (et + 25'C maximum) 2 0.323% of full scale Gain Error Orift(maximum) t 67ppmfC of full scale Offset Error (at + 25'c max.)(lin = 0, Vcm = 0) 17 LSB Offset Error (0 to + 60*C max.)(lin = 0, Vcm = 0) t 14 LSr.

Offset Error Orift(maximum)(lin = 0,Vcm = 0) t 0.2 .JBf

• VOLTAGE MODE INPUT Full Scale = 10 Volts Vcm = 0 input Range -10 Volts DC to + 10 VoltGC ILSB Input impecanca IMohm Resolution 305.176pV per LSB Overall Accuracy (at + 25'C maximum) t 0.284% of full scale Overall Accuracy (0 to + 60*C maximum) 2 0.504% of full scale Overall Accuracy Orift(maximum) 2 63ppmfC of full scale Gain Error (at + 25'C maximum) 2 0.263% % of full scale Gain Error or ft(maximum) t 57pomfC of full scale Overvoltage Protection . 220 Volts AC RMS continuously (maximum across IN + to IN - terminals)

Offset Error (at + 25'c max.)(Vin = 0, vem = 0) t 7 LSB Offset Error (0 to + 60*C max.)(Vin = 0, vcm = 0) 14 LSB Offset Error Orift (maximum)(Vin = 0 Vcm = 0) t 0.2 LSBfC e