Omron SYSMAC CS1W-ETN21 Operation Manual page 106

Section 4-1
CIO Area Allocations
Opening Flag (Bit 00)
Turns ON when an open request is received either by control bit manipulation
or the CMND(490) instruction, and turns OFF again when the open process-
ing has been completed. When CMND(490) is used, the Results Storage
Error Flag (bit 14) will turn ON at the same time as the Opening Flag turns
OFF if there is an error in the Results Storage Area designation.
Receiving Flag (Bit 01)
Turns ON if the High-Speed Option is not selected when a receive request is
received either by control bit manipulation or the CMND(490) instruction.
Remains OFF if the High-Speed Option is selected. Turns OFF again when
the receive processing has been completed. When CMND(490) is used, the
Results Storage Error Flag (bit 14) will turn ON at the same time as the
Receiving Flag turns OFF if there is an error in the Results Storage Area des-
ignation.
Sending Flag (Bit 02)
Turns ON if the High-Speed Option is not selected when a send request is
received either by control bit manipulation or the CMND(490) instruction and
turns OFF again when the send processing has been completed. Remains
OFF if the High-Speed Option is selected. When CMND(490) is used, the
Results Storage Error Flag (bit 14) will turn ON at the same time as the Send-
ing Flag turns OFF if there is an error in the Results Storage Area designa-
tion.
Closing Flag (Bit 03)
Turns ON when a close request is received either by control bit manipulation
or the CMND(490) instruction, and turns OFF again when the close process-
ing has been completed. When CMND(490) is used, the Results Storage
Error Flag (bit 14) will turn ON at the same time as the Closing Flag turns OFF
if there is an error in the Results Storage Area designation.
Data Received Flag (Bit 13)
This bit turns ON when data is received from a remote node at an open TCP
socket. Linked to this flag, the number of bytes of data saved in the reception
buffer is stored in Number of Bytes Received at TCP Socket in the words allo-
cated in the DM Area. The bit is turned OFF when a receive request is made
by either bit manipulation or the CMND(490) instruction. If any data remains in
the reception buffer after the receive request processing is complete, the
number of bytes is stored in Number of Bytes Received at TCP Socket and
the Data Received Flag turns ON again.
The status of this flag is checked before a receive request is executed.
Results Storage Error Flag (Bit 14)
Turns ON if there is an error in the Results Storage Area for a socket service
request (open, receive, send, close) made using CMND(490). This flag turns
ON at the same time as the services request processing flags (bits 0 to 3) turn
OFF. It remains ON until the next services request is received, and then it
turns OFF again. When this flag turns ON, check the set values in the Results
Storage Area.
The Results Storage Error Flag does not operate when socket services are
requested by control bit manipulation.
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