KEYENCE BL-180 - Manual (Page 102)

Power Supply BL-U1
96
4. After sending data, the BL series waits for the clear command (C).
When the clear command is sent to the BL series, the BL series clears one
piece of data received with the polling command.
When the polling command is sent to the BL series again while the BL series
is waiting for the clear command, the BL series sends back the same data
again, and waits for the clear command.
5. The same data sent in step 4 loops back to the host computer.
6. The BL series sends back OK in response to the clear command.
If the clear command is sent to the BL series when the BL series is not waiting
for the clear command (one piece of data has already been cleared), the BL
series sends back NG.
If an incorrect ID number is specified, an incorrect format is used to send a com-
mand, or a data transmission error occurs (checksum is incorrect), the BL series
sends back no response. You will need to design a program so that the same
command is sent again (Retry) if the BL series sends back no response within a
specified period (Timeout).
If the amount of stored data exceeds the capacity of the transmission buffer, the
BL series stops the read operation. To re-start the read operation, turn on the tim-
ing input again, or send the trigger ON command to the BL series again.
If you retry the clear command when the response data has been improperly
transmitted (when the checksum is incorrect), the BL series may send back NG
in response to the retried command since the clear command previously sent has
already cleared one piece of data.You will need to design a program so that both
OK and NG are regarded as acceptable responses to the clear command.
When using CODE128, do not include the control code (e.g. <STX>, <ETX>).
[STX] mmm nn C cc [ETX]
[STX] mmm nn P cc [ETX]
[STX] mmm nn C cc [ETX]
[STX] mmm nn OK cc [ETX]
[STX] mmm nn NG cc [ETX]
CAUTION