Rockwell Automation 1757-ABRIO Process Remote I/O (RIO) Communication Interface Module - Manual (Page 148)

146 Publication 1757-UM007D-EN-P - December 2008
Appendix B Operational Comparison Between the 1757-ABRIO Module and a PLC-5 System
Rack Missing Good communication bit for the rack is cleared
Good communication bits for block transfer modules in
the rack are cleared
Digital data does not update
Digital inputs hold their last state
Digital outputs go to the state set on the rack last state
switch in the rack
Block transfers to the rack do not update
Data from block transfer read modules goes to Not a
Number (NaN)
Block transfer write data goes to the state configured on
the I/O module
Tags with digital or block transfer data mapped to the
rack continue to update
Front panel displays the missing rack for 5 seconds
RIO network status indicator is red
Status bit for the rack is cleared
Block transfers to modules in the
rack error
Digital data does not update
Digital inputs hold their last state
Digital outputs go to the state set
on the rack last state switch
Block transfer read data holds its
last state
Block transfer write data goes to
the state configured on the I/O
module
Block transfer module missing or
not responding Good communication bit for the block transfer module is
never set
Block transfer doesn't update, BT ignored request
diagnostic counter slowly increments
Error with module location is entered in the scanner log
each time the BT is retried
Tags to which the module is mapped update
Initial configuration block transfer
write to the module fails, block
transfer error bit is set
Invalid configuration data to block
transfer module Can not happen, configuration program should validate
configuration Initial block transfer write to the
module fails, block transfer error bit is
set for that block transfer
Block transfer read to configured
input module fails Good communication flag for module is cleared
Input data is set to Not a Number
(1)
Block transfer read error bit is set
Input data holds last state
Block transfer write to configured
output module fails Good communication flag for module is cleared
Output data is set to a value that depends on the
module configuration or jumpers
Block transfer write error bit is set
Output data is set to a value that
depends on the module
configuration or jumpers
Flag write tag to digital rack times
out 1757-ABRIO module sets outputs mapped to the tag to the
state set on the backplane switches (last state or 0) N/A
Flag read tag times out Inputs continue to update in the 1757-ABRIO module. N/A
Numeric read tag times out Data continues to update in the 1757-ABRIO module but
nothing is reading them. N/A
Numeric write tag times out 1757-ABRIO module sets block transfer write data mapped
to the tag to the state set by the user in the module
configuration. Possible choices (last state, etc.) depend on
the module. N/A
Analog output data out of
configured range Data invalid bit for the channel is set
Output for the channel clamped to min/max value
See specific output module
documentation for appropriate
response.
Exception Conditions Comparison Between a PLC-5 System and a 1757-ABRIO Module
Exception Condition Message From 1757-ABRIO Perspective From the PLC-5 Perspective