COM Module Ports

Use COM modules to add ports to your controller. A COM module cannot follow an I/O module. COM modules must be placed next to the CPU, or may be placed next to each other.

Use the module's struct to monitor and manage communications, and the properties to configure the port to your needs.

In the properties, use the Initialize Port For drop-down option to initialize the port for general communications, serial MODBUS or for use with a modem.

Struct

Parameter Name	Data Type	Description
Success	Bit	Turns ON when message is sent successfully and the Send Status parameter=0.
Fail	Bit	Turns ON when a message fails to be sent. The Send Status parameter will be negative.
Send Status	INT16	Messages 0 - No Errors 1 - Function started 2 -Function in Progress -1 - General COM Error -10 - Tx start failed -11 - Insufficient space in buffer
Tx Packet Counter	UINT32	Read/Write The number of packets sent, increments each time a message is successfully sent via a Send Tx function. Initialized at power-up.
Rx Packet Counter	UINT32	Read/Write The number of packets received each time COM Rx receives a message. Initialized at power-up.
RTx Drop Counter	UINT32	Read/Write The number of packets dropped. Initialized at power-up.
Number of Bytes Waiting	UINT32	Number of bytes in the COM Rx buffer ( up to 1024 bytes)
Time from First Byte	UINT32	Time in milliseconds from the first byte received. Initialized each time the COM Rx function runs.
Last Bytes Waiting in Buffer	UINT8	Last 4 bytes in the Rx buffer.