IBM 3745 Series, Hardware Maintenance Reference

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Lamp Test
The 'GO' key displays all positions during 5 s on the screen to test the LEDs.
A specific key display can also be tested (by keeping that key pressed longer than
5 s).
Background Information
This is the default information that appears on the screen in normal mode. You
find, from left to right:
Ÿ
3745 line physical (or logical in case of LIC swap) address: 2 characters
Ÿ Line quality irrelevant = x: x from 0 to F (0 is the best)
Ÿ Operate OFF = x: L = Non-switched, W = Local wrap via TC
Ÿ RTS OFF = 0 ON = 1
Ÿ
RFS OFF = 0 ON = 1
Ÿ
CD OFF = 0 ON = 1
Ÿ TD blinks on TD activity, indicates also speed of transmission: F = full, B =
backup
Ÿ RD blinks on RD activity, indicates also speed of reception: F = full, B =
backup.
Notes:
1. 'WRAP' is displayed instead of line address and line quality if a manual loop
back test is running.
Transitions between 0 and 1 on the screen indicate that activity is taking place
on the lead (except for RD and TD). If there is no activity the actual status is
displayed.
2.
When CD = 0, RD indicates the speed of last data reception.
When RFS= 0, TD indicates the speed of last data transmission.
DCE Information
When the background information is displayed, keeping the ERASE key pressed
will give you a display of the form:
aaaa bbb cc
where:
aaaa 4800 bps or 9600 bps or 14 400 bps or V.27 or V.29 or V.33
bbb
Transmit clock option
Ÿ
INT for internal (from local)
Ÿ RCV for received (from remote).
cc Network configuration
Ÿ PP for point-to-point primary
Ÿ PS for point-to-point secondary
Ÿ
MC for multipoint control
Chapter 4. Transmission Subsystem (TSS)
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