Service manual

3. DIAGNOSTIC CHECK
Service Manual BSM-4100 3.15
COM RAM Check
This item checks the dual port RAM for communication between the host CPU on
the MAIN board and CPU on the DPU board. The check method is the same as the
system RAM check. The check program indicates the address, write data and read
data if an error is detected.
This RAM is located on the DPU board. Therefore if an error is detected, the DPU
board or connector which connects the MAIN and DPU boards will be faulty.
Procedure to Start, Stop, and Exit the COM RAM Check Program
1. To select the COM RAM Check, touch the “COM RAM CHECK” key. The
instrument automatically starts the RAM check.
2. If the check program finds an error, it displays the address, write data and read
data as shown in the above table.
3. To stop the check temporarily, touch the “STOP” key. The “START” key name
changes to normal and the “STOP” key is highlighted.
To continue the check, touch the “START” key again.
4. To return to the MANUAL CHECK MENU screen, touch the “RETURN” key.