...
- redundant 2-node D2000 system
- on each node running one active instance of the D2000 KOM process (SRV.KOM) monitoring the HOT process (kom /WSRV,1 /RDMYGRP and kom /WSRV,2 /RDMYGRP)
- a TCP/IP-TCP line configured on the SRV.KOM process, a station with the IEC 870-5-104 Server protocol and with input and output I/O tags
- a superior control system that communicated in parallel with both SRV.KOM processes, sending commands to a single (but arbitrary) KOM process (and expecting command confirmations from it) and expecting spontaneous values from both KOM processes.
Note: in order not to filter out commands (e.g. the I/O tag has the value FALSE, the value TRUE is received by one KOM process and is processed, the value FALSE is received by the second KOM process and is discarded because it is identical to the original value), we recommend in the configuration of the input I/O tags on the Filter tab, activate the "New time => new value" option.
Important information
- Only communication protocols with so-called redundancy support can be used in the redundancy of the communication process. Detailed information about support of redundancy for individual communication protocols is mentioned in the document Communication protocols.
- The behavior of the communication process connected to the redundant D2000 Server in SBS status is the same as the behavior of the passive KOM process. All the above-mentioned information is valid - the passive KOM process generally does not interfere with telemetry.
- If at least one instance of the communication process is running, it is not possible to start non-instance (/WSELF) and vice-versa.
- TELL command SET_ACT_INST allows to control the switching of the active communication process.
- TELL command SET_PREFERRED_INST allows setting the preferred instance of the communication process.
- We recommended installing each of instance of the communication processes on a separate computer. It enables servicing without a breakdown of the telemetry.
...