Rockwell Automation 1753-DNSI DeviceNet Safety Scanner for GuardPLC Controllers - Manual (Page 60)

Publication 1753-UM002A-EN-P - July 2005
6-4 Create a GuardPLC Project with High-Speed Safety Protocol
Use the following guidelines when setting the Controller Receive
Timeout and Controller Resend Timeout:
• In environments where no HSP retries are required, set the
Controller Receive Timeout to the amount of time required
for the controller to send the HSP request, for the scanner to
process the request, and for the scanner to send a response
back to the controller. This value can be determined by
observing the Response Time values displayed on the HSP
protocol tab of the Resource Control Panel.
Set the Controller Receive Timeout to be greater than or equal
to the maximum value reported plus a margin of safety (3 ms
or 10% of the maximum value reported). The Controller
Resend Timeout should be set to zero.
• In electrically noisy environments, configuring retries on the
HSP link may be required. Set the Controller Resend Timeout
to be equal to or greater than the Max Response Time value
reported on the HSP Protocol tab of the Resource Control
Panel plus a margin of safety (3 ms or 10% of the maximum
value reported). To enable a single retry, the Controller
Receive Timeout must be 2 times the Controller Resend
Timeout. To enable 2 retries, the Conroller Receive Timeout
must be 3 times the Controller Resend Timeout.
• The controller’s Communications Time Slice, found on the
Properties dialog of the controller Resource, must be greater
than the Controller Receive Timeout to enable proper HSP
operation. If other protocols are in use on the controller
Resource, then the Communications Time Slice should be
increased to accommodate their use in conjunction with HSP.
The Maximum Communication Time Slice setting on the
Device Properties page should be set to the Maximum
Communication Time Slice observed on the Control Panel’s
Statistics tab plus a margin of safety (6 ms or 10% of the
maximum value reported).
Refer to the GuardPLC Controller Systems User manual,
publication 1753-UM001, for more information on configuring
communications for GuardPLC controllers.
TIP
The Controller Id, Scanner Id and Scanner
Receive Timeout values are shown here for
reference. These values are set following a
successful Scanner Signals File (.ssf) import
process. For the import process to succeed, the
Controller Id must match the System ID (SRS)
of the controller Resource.