Contrec 515 FA01, Руководство по эксплуатации

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Communications
515 FA01 - 29 August 2021 59
Protocols
The communications protocols can be assigned to the communication ports
on the instrument as follows:
•
ASCII - Simple ASCII
•
RTU - Modbus RTU
•
PRN - Printer Protocol
•
NONE - If a port is not being used, set the protocol to NONE.
Note: The Printer Protocol is only available if the option with Real Time
Clock is installed. Also a protocol cannot be assigned to more than
one port at a time as described in
Communications on page 47.
•
ASCII - In this ASCII protocol each command and response is a string
of ASCII characters. This proprietary protocol is developed by Contrec
to allow for simple information interchange. The main advantages of this
mode are that it allows extended time intervals to occur between
characters without causing a timeout error and that messages can be sent
and monitored easily with a simple ASCII terminal.
•
Modbus RTU - Modbus RTU is an industry-standard protocol which
allows the instrument to be easily connected to computers running
supervisory software systems. The main advantage of this mode is that
its greater character density allows better data throughput than ASCII
mode, however each message must be transmitted in a continuous
stream.
•
Printer - In the Printer protocol there is a selection of printer types.
Please refer to the Printer Protocol on page 71 for full details.
Simple ASCII Protocol
This simple ASCII protocol requires that all requests are initiated with a
colon ( : ) and terminated with a carriage return (
C
R
). The message
termination can include a linefeed before the carriage-return (
L
F
C
R
), but it
is the carriage-return that acts as the message termination.
All responses by the instrument are terminated with a linefeed and a
carriage-return (
L
F
C
R
).
Requests Format
The format of a request to the instrument is as follows:
:A001:LR001:XXX?
L
F
C
R
Address Log Command Log
type number
Carriage-return
Linefeed