Rockwell Automation 198 Series C Modular DeviceNet Starter Auxiliary User Manual - Manual (Page 136)

A-2 DeviceNet Information
Publication 198-UM002A-EN-P December 2001
Operating Modes
The MDSA DeviceNet module has five modes of operation:
• Power-up Reset Mode
• Run Mode
• Error Mode
• I/O Error Mode
• I/O Idle Mode
Power-up Reset Mode
During power-up reset the MDSA DeviceNet module does the following:
1. Performs 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 flash green for ¼ second, red for
¼ second and then extinguish while the module finishes initialization.
3. Performs a CRC check on the EEPROM values in order to verify the configuration
data integrity. If these tests fail, the Mod/Net Status LED flashes red and goes to the
Error Mode.
4. Identifies the I/O modules attached to the MDSA DeviceNet module. Compares the
I/O modules present with the module array that is stored from previous sessions. If
they are different, the unit enters the I/O error mode, and the I/O status LED on the
unit illuminates solid red. The factory default is “no I/O modules attached”. If I/O
modules attached match the stored array of I/O modules, the I/O Status LED is off.
5. Performs other power-up initialization functions. If any of these initialization
functions fail, the MDSA DeviceNet module enters the Error Mode and the
Mod/Net Status LED turns solid red.
6. Performs auto-baud rate identification (if enabled). While the unit executes the
auto-baud rate algorithm, the Mod/Net status LED continues to blink green for ¼ s.,
then red for ¼ s.
Once the baud rate has been established, the unit performs a Duplicate MAC ID check to
verify that another node is not assigned the same DeviceNet address. If a Duplicate MAC ID
error occurs, the unit enters the Error Mode, and the Mod/Net LED turns solid red.
If the Duplicate MAC ID check is successful, the unit enters the Run Mode and the Mod/Net
Status LED flashes green.