Rockwell Automation 2706-P42_P43_P44_P72_P74_P92_P94 InView Marquee Message Display User Manual - Manual (Page 80)

Publication 2706-UM016D-EN-P - March 2006
4-14 InView Protocol
Message Format
Messages are transmitted at 9600 baud, and starts with a beginning of
frame : and ends with a carriage return (CR) line feed (LF) to indicate
the end of frame. The line feed character also serves as a
synchronizing character to indicate that the transmitting station is
ready to receive an immediate reply.
The Modbus ASCII message frame format consists of an address field,
a function field, a data field, an LRC or error check field, an end of
frame field (EOF), and a ready to receive response field (LF). The EOF
is a carriage return (0x0d), and the LF is a line feed (0x0a).
Methods of Transportation
Method Description Modbus Function
code Display Action
Add/Remove a Message
using a Broadcast
transmission Triggers a message(s) on all displays
using address 255. 10 Writes information into registers 101 and
102.
The display will give no response to
transmission.
Add/Remove a Message
using a Guaranteed
transmission Triggers a message(s) on a specific
display address. 10 Writes information into register 101 and
102.
The display will respond to the query.
Priority Messaging using a
Broadcast transmission Triggers a message on all displays using
address 255. 06 Write information into register 103.
The display will give no response to
transmission.
Priority Messaging using a
Guaranteed transmission Triggers a message on a specific display
address. 06 Write information into register 103.
The display will respond to the query.
Read register data Request information from a group of
registers in the display. 03 Transmit back the information in the
registers queried.
Variables Broadcast Update variables in all displays using
address 255. 06 or 10 Update variable registers.
The display will give no response to the
transmission.
Variable Guaranteed Update variable in a specific display
address. 06 or 10 Update variable registers.
The display will respond to the query.
Message Download Download messages to all display(s)
using a specific function code using
address 255. 01 Signals the displays that the following
data will be InView protocol. The display
will give no response to the transmission.