Rockwell Automation Publication 1734-UM013C-EN-P - August 2010
87
Configure the Module in a GuardLogix Controller
Chapter
6
The smallest input RPI allowed is 6 ms. Selecting small RPIs consumes
network bandwidth and may cause nuisance trips because other devices
cannot get access to the network.
As an example, a safety input module with only E-stop switches connected
may generally work well with settings of 50…100 ms. An input module
with a light curtain guarding a hazard may need the fastest response that is
possible.
Selecting appropriate RPIs results in a system with maximum (best)
performance.
b. Use the default values for Timeout Multiplier (2) and Network Delay
Multiplier (200).
A connection status tag exists for every connection.
If the RPI and connection reaction time limit for the network are set
appropriately, then this status tag should always remain LO. Monitor all
connection status bits to verify that they are not going HI intermittently
due to timeouts.
IMPORTANT
Analyze each safety channel to determine what is
appropriate. The default Timeout Multiplier of 2 and
Network Delay Multiplier of 200 creates an input
connection-reaction time limit of 4 times the RPI, and an
output connection-reaction time limit of 3 times the RPI.
Changes to these parameters should be approved by a
safety administrator.