Troubleshooting Communications Problems - Siemens MJ-4 Series Installation Manual

MJ-4 Communications Module
This parity selection will override any default or inherent parity defined in the selected protocol. [For example, the
2200 protocol specification document defines the parity as even. The Comm Parity configuration item allows even
parity to be selected, but it also permits the system designer/installer to use an alternate parity selection if desired.]
Comm Address
This configuration item defines the communications address for the communications module. Each device
connected on the communications link must have a unique communications address. The Comm Address setting
must correspond with the address programmed into the RTU or other supervisory device so that it can request
information from and write data to a particular MJ-4 Control Panel.
Resync Time
This configuration item defines the Communications Module resync time (in characters). This item is used for
Communications Module protocols 2200 and 2179 to determine when one message ends and another message
begins. If a new character is not received within the period specified by this parameter, the control panel assumes
that the next received character is the start of a new message.
Tx En Delay
This configuration item defines the Communications Module Transmit Enable Delay (in milliseconds), specifies the
amount of time between the RTS output being activated and the start of transmit (output) data.
DNP dl Confirm
This configuration item defines whether or not to request confirmation from the master station for all responses for
the DNP3.0 protocol
CM SW RepeatEn
This configuration item controls whether software repeat is used for the MJ3A A, B1, and B2 protocols.
Host Addr
This configuration item defines the communications address for the RTU or other supervisory device to which
unsolicited responses are sent.
CM Unsolicited
This configuration item defines whether or not the communications module should send unsolicited responses.
Note that if this parameter is "Y", an "enable unsolicited responses" message must also be sent from the master
station to start them.
AutoInhEnRemRL
This configuration item controls whether the auto inhibit must be active before a remote raise or lower request will
be followed. Setting "Y" prevents accidental fighting against the automatic tap changes with remote commands.
DNPset
This configuration item selects what DNP points will be used. Choose "DNPcfg" to configure your own points
with the DNP Configure program or choose from the preconfigured DNP point sets. See Section 8.

7.6 Troubleshooting Communications Problems

This section explains how to troubleshoot the MJ-4 Communications Module using the front panel LED indicators
and the MJXplorer software. The MJXplorer software allows you to access the communications module parameters
via the MJ-4 Control Panel.
19