Parts Lists
The following tables list the replaceable parts for the 268XA devices. PCAs may be subject to damage by static discharge. Table 7-1. 2680A Final Assembly Parts List Table 7-1. 2680A Final Assembly Parts List HOLDER,HLDR,FUSE,1 4 X 1-1 4,LOPROFILE,PNLMT 2680A-4004 PCA, SYSTEM POWER AND CONTROLLER 5500A-4417,WIRE, BINDING POST TO FASTON LC1 LINE CORD,NORTH AM,10A,5-15 IEC,18 3,SVT,7.5 FT MNO2,3.0V,0.560AH,CR2450,COIN,PC PINS,24X5MM,BULK CABLE ASSEMBLY,FLAT,20 COND,MICRO MODUL RECEPT,FERRITE,12...
Inguard Microcontroller
This microprocessor A3U5 and associated circuitry controls all functions on the A D Converter PCA and communicates with the Controller System Power PCA. Upon request by the Controller System Power PCA also called the out guard processor , the inguard microprocessor selects the input channel to be measured through the channel selection circuitry, sets up the input signal conditioning, commands the A D EPLD A3U18 to begin a conversion, stops the measurement, and then fetches the measurement...
Open Thermocouple Detect Circuitry
The open thermocouple detect circuitry uses devices A3U23 and A3U32. Before every thermocouple measurement, the open T C check is done by sending a small ac-coupled signal to the thermocouple input. The A D Microcomputer A3U5 initiates the open T C test by asserting OTC_EN and turning ON A3Q20. A 19.2 kHz square wave is sent out the OTCCLK line through A3Q20 and A3C82 to the thermocouple. The resulting waveform is detected by A3U32 pin 3 and a proportional level is stored on A3C79. If the level...
Info Uko
Figure 8-6. A D Supply Assembly cont z1 z2s3 13 z4 z5 es z6 e z7 subject to damage by STATIC ELECTRICITY WP5G-WP6 WP7Q WP80 WP9 0-WP 1 0 WP11 o-WP 1 2 G WP13 0-WP14o- KB EE R17Bil RHf JRZ7C r2sc r43 r38 r3 r40 r41 si 7 r42 -nCRl OCR17 CRjaCRlJ RaCRSRllsH ED CR10 cr11cr14 h si ssss00a a0s i00a0 I g g gSSI B S0 SI0IIS -L- C37 -L- C3B -J- C77 -L CB9 -L CBB T0.1 T0.1 T0.1 T0.1 T0.1 25V I 25V I 25V I 25V 25V -L- C37 -L- C3B -J- C77 -L CB9 -L CBB T0.1 T0.1 T0.1 T0.1 T0.1 25V I 25V I 25V I 25V 25V...
DC Fuse Replacement
The 2680A 2686A devices use a 4 ampere, 250 V, slow blow fuse in series with the dc supply input. This fuse is mounted on the main controller board inside the chassis. See Figure 3-2 for an illustration of the dc fuse location. Because of potential high voltages, this fuse should only be replaced by a Fluke qualified technician. AA'Warning The 268XA chassis contains high voltages that can be dangerous or fatal. Only qualified personnel should attempt to service the chassis. 1. Disconnect all...
Table of Contents
1 Introduction and Block 2680A 2686A Combined 2680A 2686A General Real-Time Clock and Trigger In Trigger Out Master Alarm Output Communication 2686A PC Card Precision Analog Input PAI A D Specifications PAI A D DC Voltage PAI A D AC Voltage Measurement PAI A D 4-Wire Resistance Measurement PAI A D 2-Wire Resistance Measurement PAI A D 4-Wire RTD per ITS-1990 Measurement PAI A D 2-Wire RTD per ITS-1990 Measurement PAI A D Thermocouple per ITS-1990 Measurement PAI A D Frequency Measurement Fast...