Allen-Bradley InView Marquee 2706-P42, User Manual

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Publication 2706-UM016A-EN-P - June 2002
InView Protocol 9-13
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.
Table 9.4 Modbus Function Codes used in InView Products
Function
Code Function
Code Hex Modbus
Meaning Action.
01 01 Read Coil status Used to signal the downloading messages to the display
03 03 Read Output
Registers Query Used to read registers in a display
06 06 Preset Single
Register Used to preset a single register in a display (Priority Messaging,
Update Variables, and Add/Remove a Message)
16 10 Preset Multiple
Registers Used to preset multiple registers in a display (Add/Remove a Message or Update
Variables)
Table 9.5 Methods of Transmission
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.
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