YOKOGAWA UPM100, Руководство пользователя

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4-3
IM 77C01H01-10EN
PC Link Communication
4
4.1 Overview
4.1.2 Configuration of Response
Responses from the UPM100 with respect to a command sent from the higher-level
device consist of the elements shown below, which differ depending on the condition of
communication; normal or failure.
1. Normal Communication
When communication completes normally, the UPM100 returns a character string “OK” and
data corresponding to a command.
No parameter data area for write command.
Number of
Bytes
1 2 2 2 Variable length 2 1 1
Element STX
Station
number
(ST-NO)
CPU
number
(01)
OK Parameter data Checksum ETX CR
2. In the Event of Failure
If communication does not complete normally, the UPM100 returns a character string “ER”
and error code (EC1 and EC2). (See subsection 4.1.3, “Response Error Codes”.)
• No response is made in case of an error in station number specification or CPU number
specification.
• If a UPM100 cannot receive ETX in a command, response may not be made.
Note: As a countermeasure, provide a timeout process in the communication functions of the
higher-level device or in communication programs.
Number
of Bytes
1 2 2 2 2 2 3 2 1 1
Element STX
Station
number
(ST-NO)
CPU
number
(01)
ER EC1 EC2 Command Checksum ETX CR