Internal API
All rPLC processes have a basic internal API which can be accessed via procname.plcsock UNIX socket file, automatically created either in the system temporary directory or in a directory specified in PLC_VAR_DIR system environment variable.
rplc CLI tool uses API to obtain PLC info and statistics. API can be also accessed by 3rd party programs.
API protocol
rPLC uses JSON RPC 2.0 with MessagePack-encoded payloads. The packet format is:
Byte |
Description |
|---|---|
0 |
Protocol version (0) |
1-4 |
Packet length (32-bit little-endian) |
5- |
Packet payload (MessagePack) |
API methods
Method |
Parameters |
Description |
|---|---|---|
test |
None |
returns null |
info |
None |
returns PLC name, description, version, status and PID |
thread_stats.get |
None |
returns thread stats (iterations, jitters etc.) |
thread_stats.reset |
None |
resets thread stats, returns null |