Rockwell Automation 1771-SDN DeviceNet Scanner Module Installation Instructions - Manual (Page 27)

Publication 1771-IN014B-EN-P - September 2001
DeviceNet Scanner Module Catalog Number 1771-SDN/C 27
Use the Explicit Message Program Control feature to:
•
transmit configuration data from your scanner module to its
slave devices on your DeviceNet network
•
receive status and diagnostics from these devices on your
DeviceNet network
•
make runtime adjustments to device parameters according to
changing conditions detected by your processor
How the Explicit Message Program Control Feature Works
1. Format a Block Transfer Write file in the processor to send an
Explicit Message Request to the scanner module (download).
DeviceNet
drop line
DeviceNet trunk line
Master’s Explicit
Request
Slave’s Explicit
Response
1203-GK5
Communication
Adapter
Block Transfer Write file (64 words)
(sent from processor to scanner module)
Block Transfer Read file (64 words)
(sent from scanner module to processor)
Explicit Message - A message used to transmit
commands, data, requests for data or responses.
The message is sent from a client on the Device
Net network to a server on that
network.
Request - An explicit message sent by a client
to a server requesting the server to perform
a function.
Response - An explicit message sent by a server
to a client in response to the client’s request. For
every request issued, there is a response.
4
1305 AC
drive
5
Block Transfer Read file
is completed. TXID’s
are deleted and can be
reused.