Chapter 8. Communication Functions
8-86
2) No protocol sending function block (DSND)
Function block Description
Input
REQ: Execute function block at the rising edge
CH: Set communication channel (0 ~ 1)
BYTE_CNT: The byte no. of data to send
SND_DATA: A variable name saving the data to send
(the no. of array should be equal or more than the data size)
Output
NDR: When it ends without error, this is set to 1 and remains 1 until the next
request for function block.
ERR: When an error occurs, this is set to 1 and remains 1 until the next request
for the function block.
STATUS : When an error occurs, this displays an error code
(1) Function
• When the execution condition turns On, the data is sent as many as they are designated as BYTE_CNT.
• The communication status is saved in STATUS
• When sending is completed, NDR is On for 1 scan, but if there is an error ERR Bit remains On for 1 scan.
• Error codes are saved in STATUS when errors occurred.
(2) Example program
• When the execution condition %MX000 is on, the saved data in _SND_DT is sent by 8 bytes via communication channel o.
3) Error codes
Code Error Description
06 Parameter Error Communication parameter setting error
08 Slave Device Busy Slave device is busy
09 Frame Type Error The number of sending byte is set over 255
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