ProSoft Technology MVI46-GSC - Manual (Page 21)

Installing and Configuring the Module MVI46-GSC ♦ SLC Platform
Generic Serial Communication Module
ProSoft Technology, Inc. Page 21 of 78
December 5, 2007
Object in
GSCInStat M1: File
Offset Description
Port[1].TxState 283 Port 2 transmit state:
0 = Waiting for Data to Send
1 = RTS On
2 = RTS Timeout
3 = Sending data
4 = Waiting for RTS Off
5 = RTS turned off
30 = Intercharacter Delay
31 = Intercharacter Delay
32 = Intercharacter Delay
100 = Message Delay before Transmit
101 = Message Delay before Transmit
Port[1].TxCharCnt 284 Port 2 transmit character count
Port[1].TxMsgCnt 285 Port 2 transmit block count
Port[1].ErrorWord 286 Port 2 error word
Port[0].WriteCnt 287 Port 1 bytes written from last block
Port[1].WriteCnt 288 Port 2 bytes written from last block
2.2.3 Error Word
Each port contains an Error Word containing the configuration/error status flag
word. These flags report configuration errors and receive overflow errors to the
controller. If the module is not functioning as expected, inspect the values
presented in this object. If a configuration error exists, the associated bit will be
set. A value of zero for the bit indicates the configuration value is valid. This does
not guarantee that the module is configured correctly for your application.
The Err_ROverflow bit is an important bit to monitor in the ladder logic. This bit is
set anytime data is lost on the receive port. The module will buffer all received
data until the termination condition programmed for the module exists or the
receive buffer reaches a size of 4096 bytes. When the termination condition is
met, the received data will be transferred from the module to the processor. Data
will be transferred in blocks of 256 bytes per transfer. If data is received on the
port and the termination condition is present and the last received data set has
not been completely, the Err_ROverflow bit will be set for the port and the newly
received data will be flushed from the receive buffer. Therefore, it will be lost.
This error flag is important to monitor because it will indicate when data is lost on
the receive port. The ladder logic must handle the data as fast as the module
receives it.
The following table defines each bit in the error word: