Instruction manual
Troubleshooting and Repair
138 025-9416
Symptom Possible Problems Solution
Error “no carrier...” Terminal not answering the
line
Verify that the Model 640 is operating
correctly.
Verify that the database line type
configuration settings are correct.
Verify that the matrix plug is installed in the
proper position.
Phone number dialing
string is incorrect
Select Edit, Locations in MCU to modify
the phone # field. Ensure that the entry
does not confuse local and modem
settings.
Computer calls, Model 640
responds “no carrier...”
Modem not configured for
“word result codes”
Check the modem manual for the proper
DIP switch settings.
Computer calls, Model 640
responds “connect,” but no
Line is too noisy or signal
is too quiet
Call the paging terminal and listen to the
modem tones. Try a different phone line or
modem.
“ready”
If Model 640 has console
option, console may
already be logged on
Verify that a console kit is not logged on.
Log off, if already ZLINKed. Only one
ZLINK connection can be active at any
given time.
Error “baud rate wrong OR
cable unplugged
Any one or combination of
the four errors listed
Verify the baud rate, cable hookup, and
terminal power.
OR using modem COMM
port OR terminal off”
Using MCU from a MS
Windows DOS-shell
Do NOT attempt to use MCU from
Windows. Exit to DOS and restart MCU.
Error “no response from
modem”
Phone number dialing
string is incorrect
Select Edit, Locations in MCU to modify
the phone # field. Ensure that the entry
does not confuse local and modem
settings.
Modem initialization string
is incorrect
Create or modify ‘modem.ini’ file in the
appropriate site subdirectory. See Section
4 for details.
Can’t ZLINK from a dumb
terminal (not same as
console kit)
DTR signal
miscommunication
Disconnect the DTR pin (4) and attempt to
ZLINK again. Once connection is
established, reconnect signal.
System doesn’t recognize
database changes
Modifications haven’t been
updated to the paging
terminal RAM disk
Execute the ZLINK reboot command to
initialize changes.