Comm Module Issues With The Ak-Sc255/355; Will Not Scan (Scanning Issues); I/O Network Failure - Danfoss AK-SC255 Guía De Solución De Fallas

AK-SC255/355
Does Not Communicate with
AK-SC255/355
(I/O with AK-SC255/355 Controller)
Comm module issues associated
with the AK-SC255/355

Will not scan (Scanning Issues)

I/O Network Failure

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©Danfoss (USCO / MK), 09-2011
Troubleshooting Guide / Guía de Solución de Fallas
• Check address configuration of the Comm Module associated with your I/O
and insure that it matches what you have configured.
• Check to insure that there is 24 volts present at the Comm Module.
• Cycle power to the Comm Module on the lineup with the problem.
• Rescan I/O Network.
• Check all wiring and physical connections.
• Check that all Comm Modules and associated I/O are powered on and are
addressed as configured. Remember, if you have made an address change to
Comm Module for your I/O it must have power cycled before it will hold the
new address.
• Check to see that you are scanning the correct communication buss by going
to Communications, I/O Network, Rescan Channels. If you have questions
about which buss you should be scanning for call Danfoss Technical Support
for further assistance.
• I/O Comm failures do not necessarily indicate that an individual module is
bad but rather that for some reason communication messages are getting
dropped. Check with Danfoss Technical Support for other options before
replacing the suspect module.
• Check that all Comm Modules and associated I/O are powered on and are
addressed as configured. Remember, if you have made an address change to
Comm Module for your I/O it must have power cycled before it will hold the
new address.
• Check all wiring and physical connections. See Figures 1, 2 and 3 on page 2.
• Check to see that you are scanning the correct communication buss by going
to Communications, I/O Network, Rescan Channels. If you have questions
about which buss you should be scanning for call Danfoss Technical Support
for further assistance.
• This message indicates that the AK-SC255/355 does not see any attached I/O.
• Check that all I/O powered on and is addressed as configured. Remember, if
you make an address change to Com Mod for your I/O it must have power
cycled before it will hold the new address.
• Check to see that you are scanning the correct communication buss by going
to Communications, I/O Network, Rescan Channels. If you have questions
about which buss you should be scanning for call Danfoss Technical Support
for further assistance.
• Fig. 1 on page 3 shows a TP-78 unit with a full row of 5 LON terminals. An RS-
485 version is also available. Note: it is important that you have the correct
Comm modules to match the specific type of AK-SC255/355 that you have.
USOC.EI.RF0.D2.ML / 521U0197 5