Nortel North American DMS-100 Instruction Manual page 440

Testing the operation of ANI and COIN voltages
Application
The LCM COVREX command is used to test the proper operation of the ANI
and COIN voltages. There can be 2 LCMs in a LCE bay. The ANI /COIN
voltages are provided by the 2 ring generators (RG) packs. RG 0 provides ANI
/ COIN voltages to unit 0 of both LCMs. RG 1 provides ANI / COIN voltages
to unit 1 of both LCMs. The voltages are wired from the RGs to the power
converters in the corresponding LCM units.
The line card in drawer 0 slot 0 of the LCM is used in the COVREX test. A
MTU or LTU is connected to this line card via the test access bus so it can
measure the ANI / COIN voltages
Note: If available, a MTU will always be used.
This is accomplished by the operation of relays in the power converter pack to
"cut-thru" the different voltages to the line card one at a time so that the MTU
can measure them. The LCM processor pack in the unit controls the operation
of the relays in the same unit's power converter.
With both units of a LCM in service, unit 1 has no access to the line card in
drawer 0 slot 0. Therefore, the first thing that happens in the COVREX is that
unit 0 goes SYSB so that unit 1 has access to the line card in drawer 0 slot 0.
After the voltages from unit 1 have been tested, unit 0 is returned to service.
Unit 0 then has access to the line card in drawer 0 slot 0 and the voltages for
unit 0 are tested.
There are five different tests per LCM unit that are run as a part of the
COVREX test. They are listed below in the order in which they are performed:
• Powercard-short
• Ring-generator
• Powercard-open
• Coin collect
• Coin return
If one of the five tests fails on LCM Unit 1, no more tests are run Unit 1. The
tests begin again on LCM Unit 0. Four asterisks are used to indicate a test has
not been run because a previous COVREX test failed. COVREX test results
can be seen by posting a LCM at the MAPCI;MTC;PM level and typing the
command TST COVREX QUERY. The TST COVREX QUERY command
will display the results of each of the 5 tests that are performed as a part of the
COVREX test along with the expected voltage range for each test.
DMS-100 Family Trouble Locating and Clearing Procedures Volume 2 of 2 LET0015 and up
Trouble locating and clearing procedures -3