Rockwell Automation 2706-P42_P43_P44_P72_P74_P92_P94 InView Marquee Message Display User Manual - Manual (Page 76)

Publication 2706-UM016D-EN-P - March 2006
4-10 InView Protocol
Or
Update Variable on a Specific Display
Update variable 5 with the value of 87 on display address 006.
Update a Variable on a Specific Display
Modbus ASCII Protocol to
Download and Preview
Messages 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.
Master and Slave Query/Response Cycle
Name [CTRL][V] Variable Data Backslash Variable # Backslash Display
address Return
ASCII ^V 2395 \ 0 \ 255 ^M
Hex \16 \32\33\39\35 \5C \30 \5C \32\35\35 \0D
Name [CTRL][V] Variable Data Backslash Variable # Backslash Display
address Return
ASCII ^V 87 \ 5 \ 6 ^M
Hex \16 \38\37 \5C \35 \5C \36 \0D
Slave Address
Function Code
Data
Error Check
Slave Address
Function Code
Data
Error Check
Master Slave