Note that the UniStream CPU port communicates at the fastest rate.
In addition to implementing MODBUS via the configuration method, and implementing MODBUS via Aperiodic (Ladder Triggered) Functions, you can use the Advanced MODBUS ladder functions to communicate with external devices.
The ladder functions listed below can run via serial or TCP/IP channels in UniStream's CPU, HMI panel, or COM modules.
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Note that the UniStream CPU port communicates at the fastest rate. |
When you include one of these functions in your program, UniLogic includes structs that enable you to implement the protocol.
MODBUS Read Builder, MODBUS Read Parser
The Read Builder accesses a slave device to read data; the Read Parser stores the data into the structs you select.
Use these functions to request and receive data from external devices.
MODBUS Write Builder, MODBUS Write Parser
The Write Builder enables data to be written to another device; the WriteParser stores the data into the structs you select.
Use these functions to write data to an external devices.