Rockwell Automation 1753-DNSI DeviceNet Safety Scanner for GuardPLC Controllers - Manual (Page 50)

Publication 1753-UM002A-EN-P - July 2005
5-8 Configure DeviceNet Nodes and Connections
When a standard connection is dropped, status bits in the
scanner identify that the slave is not online. Slave behavior
when a connection is dropped is a function of the slave device.
If the slave is an I/O device, the standard outputs will be
cleared, held at last state, or set to a fault condition (refer to the
slave device’s documentation for actual I/O behavior when a
connection is dropped).
When an input connection is dropped, the scanner sets the
corresponding data in the data tables sent to the GuardPLC
controller via the HSP connection to the safety state (0).
The EPR default value is 75 milliseconds.
• Transmit Retries – Transmit Retries specifies the number of times
the scanner attempts to retransmit a change of state or cyclic
message that has not been acknowledged by the slave device
before dropping the connection.
Create a Scanlist
The scanlist defines the standard devices (nodes) with which the
scanner is configured to exchange I/O data.
IMPORTANT
Changing the EPR number should be done
carefully because it effects how long it takes the
scanner to detect a missing device.