Using the I/OBus Port
174 870 USE 101 10 V.2
Network Status Indication in the M1 Ethernet Module
Overview The M1 Ethernet Module can provide I/OBus network status via the Module Status
function in the programming panel or by a STAT element in user logic. The fourth
word of the status element contains information regarding the integrity of the
network.
Operation The I/OBus status word contains a valid value only when the processor is running.
A zero value indicates that normal I/OBus communication is occurring.
A non-zero value indicates a problem.
Failure
Indication If there is a communications error, bit values in the I/OBus status word contain
information on the failure mode, as follows:
BITS 0 - 14 These bits contain a value from 1 to 255, signifying the network position of the
module that cannot be reached. For example, a value of 8 indicates a
communications failure in accessing the 8th module on the network.
BIT 15 This bit contains a value of 0 or 1.
A value of zero indicates a general communication failure, for example, no power to
the module or a break in its input cable.
A value of 1 indicates that communication is possible, but the I/OBus ID received
from the module does not match the module type contained in the traffic cop for
that position.