Table of Contents
Advertisement
4-8
Chapter 4: InView Protocol
Name
[CTRL][V]
ASCII
^V
Hex
\16
Section 4.4 Update Variable on a Specific Display
Name
[CTRL][V]
ASCII
^V
Hex
\16
Section 4.5 Modbus ASCII Protocol to Download and Preview Messages
Section 4.6 Master and Slave Query/Response Cycle
User's Manual 0300277-03 Rev. A
OR
Variable
Backslash
Data
2395
\32\33\39\35
Update variable 5 with the value of 87 on display address 006.
Update a Variable on a Specific Display
Variable
Backslash
Data
87
\38\37
Modbus ASCII is an industrial data communications protocol that has been
implemented in Allen-Bradley's InView Protocol. It is a master and slave
protocol providing for one master and up to 247 slaves. Each slave is assigned a
unique address, because only the master can initiate a transaction. The protocol
controls the query and response that takes place between master and slave
devices as in Figure.
The Modbus ASCII protocol is incorporated into the InView Industrial Protocol
that allows displays to connect to a Modbus ASCII communications network.
These displays receive applicable Modbus ASCII protocol and limited InView
Sign Communication protocol (used during the download and preview of
messages). Messages are pre-loaded into the displays, and then triggered by
writing Modbus ASCII instructions to specific registers in the display.
Below are several terms used throughout the Modbus ASCII section.
ASCII–American Standard Code for Information Interchange.
•
LRC–Longitudinal Redundancy Check used for error checking.
•
RTU–Remote Terminal Unit.
•
•
Query–Sending information to a node address where a response is
expected.
Response–A response is given to a Query.
•
•
Transmission–Sending information to all node addresses where no
response is expected.
Variable
Backslash
#
\
0
\5C
\30
Variable
Backslash
#
\
5
\5C
\35
Display
Return
Address
\
255
\5C
\32\35\35
\0D
Display
Return
Address
\
6
^M
\5C
\36
\0D
^M
Advertisement
Table of Contents
Need help?
Do you have a question about the Spectrum Controls 2706-P22-SC and is the answer not in the manual?