Overview
This control variable is used to clear the Send buffer, Receive buffer, and error status. This control variable is write-only.
Format
If bit is specified [c:EXT_SIO_CTRL**](**:00 to 15)
If word is specified [c:EXT_SIO_CTRL]
Example expression:
When designating a bit [c:EXT_SIO_CTRL00] = 1
When designating a word [c:EXT_SIO_CTRL]= 0x0007
Contents of EXT_SIO_CTRL
When a word is selected, and two or more bits are set simultaneously, the processing is executed in the following order.
Clear error → Clear receive buffer → Clear send buffer
Clear error clears the value in status bits 1 (send error) and 3 (receive error).
When using the GP4000 Series, LT4000 Series, ST6000 Series, ET6000 Series, STM6000 Series, STC6000 Series, or SP5000 Series (excluding Open Box), bit 0 and bit 1 are "receive buffer clear" and "send buffer clear".
Overview
Status includes the following information.
This status variable is write-only.
Format
If bit is specified [c:EXT_SIO_CTRL**](** :00 to 15)
If word is specified [c:EXT_SIO_CTRL]
Example expression:
When designating bit if([s:EXT_SIO_STAT00] == 1)
When designating word if(([s:EXT_SIO_STAT] & 0x0001) <> 0)
Contents of EXT_SIO_STAT
The reserved bits may be assigned in the future. Therefore, be sure to check only the necessary bits.
Two types of transmission errors exist: the transmission timeout error and the transmission buffer-full error. When either of the two errors occurs, the transmission error bit turns ON. The transmission timeout period is five seconds.
There are four types of receive errors: parity error, overrun error, framing error, and overflow. When one of these four errors occurs, the bit for the receive error turns ON.
If a transmission error is detected, the send data remains in the transmission buffer. If a transmission error cannot be detected, the send data is sent from the transmission buffer.
When using the serial interface COM2, which is RS-422, the CS (CTS) signal cannot be detected. As a result, disconnection of a cable cannot be detected.
Overview
Shows the quantity of data (number of bytes) received at that time. The received data size is read-only.
Format
[r: EXT_SIO_RCV] is the script for Receive Data Size (number of bytes) in GP-PRO/PB III V.6.0 or earlier, This script is supported and does not need to be edited. This function runs the same whether you use [r: EXT_SIO_RCV] or [r: EXT_SIO_RECV] as your expression.