Service manual

2. Measure Channel 08 GU Resistance
– Send *RST to multiplexer
– Send CLOS (@nn08) to close chan 08, where nn = card #
– Trigger the DMM with TRIG SGL and note reading
– Send OPEN (@nn08) to open channel 08
– Subtract measured value of R25 from DMM reading
– Enter the result in Table 2-2 for Channel 08 GU
3. Repeat for Channels 09 - 15 GU and Channels 91 - 92 GU
– Repeat steps 1 and 2 for channels 09 - 15 GU and 91- 92 GU
– Use CLOS (@nncc) and OPEN (@nncc), where nn =
card # and
cc = channel # (omit leading zeroes in nn)
– For Channel 91 GU, subtract combined value of R25 + R31
– For Channel 92 GU, subtract combined value of R25 + R28
Example: Closed
Channel Resistance
Test
The following program performs a Closed Channel Resistance Test on
Channels 00 - 15 and 90 - 92 HI, LO, and GU. If the contact resistance for a
channel is >2.0 Ω, the program displays the message "Resistance for
Channel chan Relay is >2.0 Ohms" and stops.
NOTE Since small measurement variations occur when measuring the protection
resistors, the program returns "0.00" if the calculated resistance is <0 Ω.
10 ! RE-SAVE "CLOS_TEST"
20 ASSIGN @Dmm TO 722
30 ASSIGN @Mux TO 70914
40 DISP CHR$(129)
50 DIM R(20:31),Value0(8,2),Value1(9,2),Result0(8,2), Result1(9,2),
Path$(2)[2]
60 DATA HI,LO,GU
70 READ Path$(*)
80 !
90
!Measure protection resistors
100 !
110 PRINT "Measure Protection Resistors R20 - R31 "
120 PRINT TABXY(1,3)," 1. Turn mainframe power OFF"
130 PRINT TABXY(1,4)," 2. Remove E1345A Component Assembly
from mainframe"
140 PRINT TABXY(1,5)," 3. Set DMM for 4-wire ohms (OHMF) function
"
150 DISP " Press Continue when ready to measure protection resistors "
160 PAUSE
170 CLEAR SCREEN
180 FOR I=20 TO 31
190 PRINT TABXY(1,4),"Connect DMM leads (4-wire) to resistor R";I
Continued on Next Page
Chapter 2 Verification Tests 29