Rockwell Automation 198x Modular DeviceNet Starter Auxiliary I/O - Manual (Page 142)

A-2 DeviceNet Information
Publication 198-UM001B-EN-P September 2001
DeviceNet Implementation
The DeviceNet Implementation in the cat. no. 198-DN and 198-DNG modules is compliant
with the DeviceNet Specification Volume I, version 2.0, and Volume II, version 2.0. It allows
the unit to reside on a DeviceNet network as a Group 2 slave type device. Explicit messaging
(sometimes referred to as client/server) is supported for device configuration on the network.
Polled I/O messaging, Change of State (COS) messaging, and Cyclic I/O messaging are
supported to pass control/status information from/to a DeviceNet master device.
An autobaud rate identification algorithm is executed on power-up (if enabled).
A Group 4 recovery of faulted node algorithm is executed if the device fails its power-up
Duplicate MAC ID test and the unit MAC ID is software settable.
The outputs are controllable via explicit messaging only to the extent that it is permitted by
the explicit control algorithm for explicit control.
Operating Modes
The MDSA DeviceNet code has four modes of operation:
• Power-up Reset Mode
• Run Mode
• Error Mode
• I/O Error Mode
Power-Up Reset Mode
During power-up reset, the cat. no. 198-DN module performs the following sequence of
operations:
1. Perform a CRC check on the ROM. If this test fails, the product will attempt to turn
the Mod/Net Status LED solid red and go to the unrecoverable Fault State.
2. The Mod/Net Status LED and the I/O Status LED flashes green for 1/4 second,
red for 1/4 second, and then extinguishes while the 198-DN finishes initialization.
3. Performs a CRC check on the EEprom values stored in order to verify the data
integrity. If these tests fail, the Mod/Net Status LED flashes red and goes to the
recoverable Fault State.
4. Identifies the I/O modules attached to the MDSA DeviceNet module. Compares
with the EEprom configuration stored from previous. If they are different, the unit
enters the I/O error mode and the I/O Status LED on the unit illuminates red. The
out-of-the-box default is no I/O modules attached. If the configuration is correct, the
I/O Status LED is off.