ProSoft Technology 5201-DFNT-104C - Manual (Page 68)

Mailbox Feature (x201-DFNT-104C) 104C Version 3 ♦ ProLinx Gateway
Protocol Manual IEC 60870-5-104 Client (Firmware v3.xx)
Page 68 of 139 ProSoft Technology, Inc.
August 4, 2011
The start of the mailbox area is configured through the Mailbox Offset parameter
in the IEC-104 Client Module section as follows:
The mailbox area requires a 128-word database area. The first 64 words are
used for the mailbox request area received from the remote Ethernet/IP device.
The last 64 words are reserved for the mailbox response built by the gateway
module. So for the example above:
In the mailbox request area the first and last words are reserved for the mailbox
ID. Once the module recognizes a new mailbox ID (same mailbox ID) into these
registers it will process the mailbox request starting from the second register:
Offset Description
0 Mailbox ID
1 Start of mailbox request
… …
62 End of mailbox request
63 Mailbox ID