I.S. INTERCOM
20-278-12
TYPE ABMA4 USER MANUAL
15 OF 21
Issue: 05
7. SYSTEM TEST AND FAULT FINDING
The ABMA4 has a graphical display that can aid in fault finding along with the PSA Controller and End Unit.
The primary system test and fault analysis occurs when the PSA Controller gets a confirmation from the end
unit. The TEU (tail end unit) returns a signal via the S-Line and the user can hear a ‘hee’-‘haw’. If the user
only hears a ‘hee’ or single tone pair then PSA Controller has not got a confirmation. The ABMA4 helps by
displaying the system cable status by showing the R-Line, V-Line and S-Line states.
In Generic Display mode (see Generic Display Description section) you can view the R-Line voltage bar-
graph and the PSA Loop status at a glance. Alternatively you can go into ‘Menu Setting’ to the ‘Comms Line’
menu and get more information on R-Line digital reading and the time the ‘Last PSA occurred. Below is a
flow diagram of a System Test.
Flow Diagram Description
Following the right hand side of the diagram, you need to have a PSA confirmation from the controller and
each of the ABMA4’s has a PSA Loop to confirm status to get a System Test Passed. You should check that
the ‘Last PSA Confirm’ time is correct by going into ‘Comms Line’ menu (see Configuration Menu Description
and Fault Analysis below). If you get a PSA confirm from the controller but a ABMA4 unit doesn’t show PSA
Loop confirmation then fault is not in the system cable but between this cable and the unit itself (i.e. V and S
lines crossed or cut etc..).
If you do not get a PSA confirmation from the controller, then you need to read the section on Fault Analysis.
Fault Analysis
Fault Analysis of the system looks at the PSA Loop graphic of the ABMA4 to work out where on the line is a
fault. Possible reasons that a PSA controller does not receive a confirmation are as follows:
1. End Unit is not connected or has not enough volts (cable too long or two many units or system has
be used heavily and now all units are drawing maximum current).
2. There is break in the V-line between the PSA Controller and TEU
3. There is break in the S-line between the PSA Controller and TEU
4. There is break in the R-line or M-line between the PSA Controller and the TEU
SYSTEM TEST
Do we get a
PSA Confirm?
Does each
ABMA4 show
PSA Confirm?
Faulty System
See Fault Analysis
Termination fault
between ABMA4 and
system cable!
System Test
Passed
