Rockwell Automation 2706-P42_P43_P44_P72_P74_P92_P94 InView Marquee Message Display User Manual - Manual (Page 84)

Publication 2706-UM016D-EN-P - March 2006
4-18 InView Protocol
Example of a Target Holding Register
Target holding register 40102 – 40001 = 101 (0x65)
Format for the following sections is the use of a query/response or a
transmission. Each section shows the complete transmission and
response (if applicable). In some examples, there are multiple steps
that are needed to complete the function requested. Within these
steps, there are pause or delay times that must be used in-between
each step.
The data that is sent is ASCII information and the CR and LF
represents 0x0d and 0x0a respectively. The beginning of frame (:)
represents (0x3a).
Heartbeat Function
The heartbeat function, when enabled, allows the display to
determine if it is no longer on the network or if the host device is not
functioning properly (not sending data or a heartbeat). Should the
display not see any serial activity (valid or invalid) within 3 seconds,
an error message No Network Activity is displayed. The heartbeat is
either enabled or disabled via protocol or software.
Factory Default: DISABLED.
Enable the Heartbeat Function
The displays are shipped with the heartbeat disabled. Should the
heartbeat function be required, the following string of information
enables the display to look for a heartbeat or serial activity.
Transmission:
Transmission for Enabling the Heartbeat Function
Beginning
of Frame ADDR FUNC H.O.
ADDR
L.O.
ADDR
DATA LRC
Error
EOF Ready to
rec. resp
: FF 06 00 65 FFFF 98 CR LF
Beginning
of Frame ADDR FUNC H.O.
ADDR
L.O.
ADDR
DATA EOF Ready to rec. resp
: FF 01 00 64 ^AZFF^BE01^D9C CR LF