136
Changes from Previous Products Section 4-5
Response Wait Time After Host Computer Sends Data
When response wait time has been set in the command format from the host
computer, commands to the host computer will not be transmitted until the
response time has elapsed (1). Transmission of responses to commands from
the host computer will be postponed until the command transmission to the
host computer has been completed (2).
When a response is not required from the host computer, the Communica-
tions Port Enabled Flag will turn ON when the command to the host computer
has passed from the CPU Unit to the port.
4-4-5 Reception Buffers
In Host Link mode, each port has a reception buffer of 1,200 bytes. This is suf-
ficient to hold the maximum Host Link frame length for an FA command
response frame (1,115 bytes) + 85 bytes. If a frame larger than 1,200 bytes is
sent from the host computer (from @ to the carriage return), the frame will be
discarded and no response will be returned.
4-4-6 Error Responses
When Host Link FA commands are used for FINS commands, an error code
will returned as the end code in the FINS response whenever there is a mis-
take in the FINS command settings or an FINS response is required that is too
long for the legal response frame.
An end code of 110B Hex is returned when the response exceeds the maxi-
mum response length. The Host Link response frame will contain the
requested read data after the end code through the end of the maximum legal
response frame length.
Note We recommend programming retry processing at any device sending com-
mands in case noise or other factors result in transmission errors.
4-5 Changes from Previous Products
There are differences between Host Link Systems created using the CS/CJ-
series Serial Communications Boards and Unit in comparison to Host Link
Response Required
Host computer
Command
Command
Response
Response
Serial Communications
Board/Unit
Communications Port Enabled Flag
Command acknowledged
Command completed
No Response Required
Host computer
Serial Communications
Board/Unit
Command
Command
Response
Communications Port Enabled Flag
Command acknowled
ed Command completed
Response wait time
Response wait time
(1)
(2)
(1)
(2)
To Next Page
Loading...
Need help?
General
