Gasboy 1000 Series FMS Diagnostic Manual - Manual (Page 111)

GASBOY Series 1000
6-26 03/07/03
Possible Cause Checks Corrective Action
Defective Auxiliary
Communications Port PCB or
MPU PCB. Connect the RS-422 loopback
jumper to the appropriate
connector (RS-422 or RS-232)
of the Auxiliary
Communication Port PCB.
Use the TM command to
access the tank monitor.
Begin typing characters on the
data terminal. With the
exception of the first character
typed, all characters typed
should display on the data
terminal. If you are unable to enter the
tank monitor mode or the
typed characters do not
display on the data terminal,
replace the Auxiliary
Communication Port PCB.
Replace the MPU PCB if
replacing the Auxiliary
Communication Port PCB did
not allow the loopback test to
work.
No power to short haul modem
(SHM) (if RS-422
communication is used). Using AC voltmeter, measure
AC outlet which powers SHM
transformer. Is 115VAC
measured?
Remove cover to SHM and
measure DC voltages. Pin 1:
ground, Pin 2: +5VDC, Pin 3:
+12VDC, Pin 4: -12VDC.
Turn on breaker, if off.
Replace breaker if 115VAC is
not switched through it.
Repair wiring or receptacle if
115VAC is not measured.
Replace SHM transformer if
any DC voltages are missing.
Defective cabling or short haul
modem (if RS-422) or tank
monitor. Disconnect the communication
cable from the tank monitor
and connect it to the RS-232
loopback connector. (See
Note 1) Using the TM
command on the data
terminal, access the tank
monitor. Begin typing
characters on the data
terminal. With the exception
of the first character, all
characters typed should
appear on the data terminal. If RS-232 communication and
loopback test fails, repair
cabling.
If RS-422 communication and
loopback test fails, use an
ohmmeter to check cabling
from Series 1000 post to short
haul modem. Repair cabling if
shorts or opens are measured.
Replace short haul modem if
cabling is good.
If loopback test passes, repair
tank monitor. See Note 2.
NOTE 1: For RS-232 communication only: when performing a loopback test, attach a jumper
wire between positions 2 & 4 of the auxiliary port terminal block in the Series 1000
post.)
NOTE 2: If RS-232 communication, before repairing tank monitor, use an ohmmeter to verify
wire from auxiliary port terminal block position 4 to position 20 of the RS-232D
connector is good. This line is not tested with the loopback test. Repair the line if it is
open or shorted to any other lines.