...
**** - ASDU 250 can be used for communication with Ipesoft 870-5-104 Server. The command will ask for historical values (within any interval) from the server, which get back as ASDU 251 (or newer ASDU 249 that use 64-bit values for improved precision, if the protocol parameter
D2H64 is enabled on the server). The reading of the archive values can be executed by means of the TELL command
GETOLDVAL with the parameter containing the name of the I/O tag or station (in this case, there are read values of all I/O tag in successive steps, i.e. reading another tag starts after termination of currently read tag).
Response for ASDU 250 is again ASDU 250 (with CauseOfTransmission=7) and with the return code:
...
| Command | Syntax | Description |
| STCOMMAND | STCOMMAND StationName DISCONNECT | Tell command closes immediately the active TCP connections of the communication line (a parent of "StationName"). Then the connection is restarted and re-connected. |
| STWATCH | STWATCH StationName | Tell command sends Interrogation Command and/or Counter Interrogation Command to the station (depending on station parameters). |
...
**** - ASDU 250 can be used for communication with Ipesoft 870-5-104 Server. The command will ask for historical values (within any interval) from the server, which get back as ASDU 251 (or newer ASDU 249 that use 64-bit values for improved precision, if the protocol parameter
D2H64 is enabled on the server). The reading of the archive values can be executed by means of the TELL command
GETOLDVAL with the parameter containing the name of the I/O tag or station (in this case, there are read values of all I/O tag in successive steps, i.e. reading another tag starts after termination of currently read tag).
Response for ASDU 250 is again ASDU 250 (with CauseOfTransmission=7) and with the return code:
...
| Command | Syntax | Description |
| STCOMMAND | STCOMMAND StationName DISCONNECT | Tell command closes immediately the active TCP connections of the communication line (a parent of "StationName"). Then the connection is restarted and re-connected. |
| STWATCH | STWATCH StationName | Tell command sends Interrogation Command and/or Counter Interrogation Command to the station (based on station parameters). |
...