SERIAL_R[0...1]: Serial Line Read-Only System Variables

Introduction

SERIAL_R is an array of 2 SERIAL_R_STRUCT type. Each element of the array returns diagnostic system variables for the corresponding serial line.

For the M241 Logic Controller:

oSerial_R[0] refers to the serial line 1

oSerial_R[1] refers to the serial line 2

Variable Structure

This table describes the parameters of the SERIAL_R[0...1] system variables:

%MW	Var Name	Type	Comment
Serial Line
n/a	i_udiFramesTransmittedOK	UDINT	Number of frames successfully transmitted.
n/a	i_udiFramesReceivedOK	UDINT	Number of frames received without any errors detected.
n/a	i_udiRX_MessagesError	UDINT	Number of frames received with errors detected (checksum, parity).
Modbus Specific
n/a	i_uiSlaveExceptionCount	UINT	Number of Modbus exception responses returned by the logic controller.
n/a	i_udiSlaveMsgCount	UINT	Number of messages received from the Master and addressed to the logic controller.
n/a	i_uiSlaveNoRespCount	UINT	Number of Modbus broadcast requests received by the logic controller.
n/a	i_uiSlaveNakCount	UINT	Not used
n/a	i_uiSlaveBusyCount	UINT	Not used
n/a	i_uiCharOverrunCount	UINT	Number of character overruns.
n/a means that there is no predefined %MW mapping for this system variable. Not used means that the variable is not maintained by the system, and that if the value of the variable is non-zero, it should be considered extraneous.

The SERIAL_R counters are reset on:

oDownload.

oController reset.

oSERIAL_W[x].q_wResetCounter command.

oReset command by Modbus request function code number 8.