Honeywell Controller C70 CPU 900C70-0360-00
Item Status Possible Cause Controller Action What to do MODULE ERROR One of the module 
diagnostics in the 
associated rack is set 
to MISMATCH, BAD 
MODULE, BAD 
CHANNEL., or 
MISSING/NO COMM 
(if the 
communications is 
failing due to the 
module not 
installed—could occur 
if the module is 
installed but CPU 
can’t communicate toit).
Select I/O from the menu 
to see details on the faulty 
module. See I/O Module 
Diagnostics on page 42. 
Select I/O from the menu to see details 
on the faulty module. See I/O Module 
Diagnostics on page 42. 
MODULE HI CJ 
TEMP 
One of the module 
diagnostics in the 
associated rack is set 
to HI CJ 
TEMPERATURE. 
Select I/O from the menu 
to see details on the faulty 
module. See I/O Module 
Diagnostics on page 42. 
Select I/O from the menu to see details 
on the faulty module. See I/O Module 
Diagnostics on page 42. 
 FAILURE The Controller 
module is unable to 
successfully 
communicate to any 
modules that are in its 
SPI backplane. 
All associated module 
diagnostics are set to 
MISSING/NO COMM. 
See MISSING/NO COMM 
in Table 22 I/O Module 
Error Status on page 44 for 
further details. 
1. Remove modules and check for bent 
pins on connectors. 
2. Reinsert modules one at a time and 
note which module the diagnostic 
reoccurs, and replace that module. 
3. Cycle power to the rack. 
4. Replace the power supply. 
5. Replace the rack. 
6. Replace the CPU board. 
 NO COMM The Main CPU is 
unable to successfully 
communicate to an 
expansion rack that is 
in its configuration. 
See FAILURE. 1. Verify that the expansion rack should 
be in the configuration 
2. Verify that the jumpers on the 
scanner are setup for the correct rack 
address. 
3. Check that expansion rack is on. 
4. Check the expansion rack’s status 
LED for diagnostic information. 
5. Check that cable is connected to 
expansion rack. 
6. If a hub is used, check that all cables 
are properly connected to the hub, 
proper crossover cables are used, and 
that hub is powered. 
7. Cycle power to the rack. 
8. Cycle power to the hub. 
9. Replace the expansion rack’s power 
supply. 
10. Replace the expansion rack. 
11. Replace the expansion rack’s 
scanner board. 
12. Replace the main CPU.

Item Status Possible Cause Controller Action What to do 
BAD VERSION The Main CPU 
determined that its 
software is not 
compatible with the 
scanner module. 
All associated module 
diagnostics are set to 
MISSING/NO COMM. 
Refer to MISSING/NO 
COMM diagnostic for 
further details. 
1. Upgrade the scanner software either 
by replacing the module or doing a 
code-download. 
2. Update Main CPU software either by 
replacing the module or doing a code 
download. 
RTC Status GOOD N/A N/A N/A 
NOT 
PROGRAMMED 
RTC not programmed 1. Time and date is set to 
00:00:00, January 1, 1970. 
2. Associated rack monitor 
block’s RACK OK pin is 
turned off. 
3. SYSTEM MONITOR 
block’s HW OK pin is 
turned off. 
Program RTC. 
BAD DATA Bad date and time See NOT 
PROGRAMMED. 
1. Program RTC. 
2. Cycle power. 
3. Replace CPU. 
4. Replace boards in rack. 
5. Replace rack. 
PROGRAMMING 
FAILURE 
RTC failed to program See NOT 
PROGRAMMED. 
See BAD DATA. 
READ FAILURE Unable to read RTC See NOT 
PROGRAMMED. 
See BAD DATA. 
Comm Port 
Status (Rack 1) 
IO Comm 
Link Status 
(Rack 2-5) 
Good N/A N/A N/A
Item Status Possible Cause Controller Action What to do 
Data Link Failure The communications 
to a particular rack is 
resulting in a lot of 
DLL errors. 
1. Related rack monitor 
block’s RACK OK pin is 
turned off. 
2. Depending on the 
nature of the DLL errors, 
the associated rack 
monitor block’s module 
diagnostics, and pins 
could be affected. 
1. Use the OI to determine which rack 
is experiencing the DLL errors. Verify 
that the expansion rack should be in 
the configuration 
2. Verify that the jumpers on the 
scanner are setup for the correct rack 
address. 
3. If a hub is used, check that all 
cables are properly connected to the 
hub, proper crossover cables are 
used, and that hub is powered. 
4. Cycle power to the rack. 
5. Cycle power to the hub. 
6. Replace the HC900-C50 expansion 
rack’s power supply. 
7. Replace the HC900-C50 expansion 
rack. 
8. Replace the HC900-C50 expansion 
rack’s scanner board. 
9. Replace the main CPU. 
Hardware Failure The power-up test of 
the expansion rack 
Ethernet controller 
failed. 
1. All rack monitor block 
XIO PORT DIAG are set 
to HWFAIL. 
2. All rack monitor block 
RACK OK pin are turned 
off. 
3. All modules in the 
configuration have their 
diagnostic set to 
MOD_NOCOMM, their 
rack monitor module fail 
pin is turned on., and the 
rack monitor block’s 
RACK OK pin is turned 
off. 
4. ASYS block’s HW OK 
pin is turned off. 
5. The statuses for the AO 
and AI channels that are 
affected are set to 
BAD_CHANNEL. 
Replace main-CPU module 
Port A/B Cable 
Mismatch 
C70R only. The I/O 
cables from CPUA 
and CPUB are 
connected to the 
wrong ports on the 
I/O scanner CPU 
Controller continues to run 
but is not able to access 
the I/O on the associated 
rack 
Swap the cables so that I/O A is 
connected to I/O on CPUA and I/O B 
is connected to I/O on CPUB