2 bus error – Rockwell Automation 61C501 AutoMax/AutoMate 115V Input Module User Manual

Page 21

5Ć3

5.2

Bus Error

Problem: A 31" or 50" through 58" appears on the Processor

module's LED in DCS5000/AutoMax systems. In AutoMate systems,

a 1" appears in any bit location if register 3764 of an AutoMate 30 or

there was a bus error when the system attempted to access the

module. The possible causes of this error are a missing module, a

module in the wrong slot, or a malfunctioning module. It is also

possible that the user is attempting to write to registers on the

module. Refer to the instruction manual for the Processor module in

the rack for more information. Use the following procedure to isolate

a bus error:
Step 1.

Verify that the input module is in the correct slot and, for

DCS5000/AutoMax systems, that the I/O definitions are

correct.
Verify that the slot number being referenced agrees with

the actual slot number of the module. In DCS

5000/AutoMax systems, this module's register number is

always zero. Verify that the bit number refers to the proper

bit. Note that the bit number and wire number are not the

same.
For remote I/O installations, (DCS5000/AutoMax systems

only) also verify that the master slot and remote drop

number are defined correctly.

Step 2.

Verify that the module can be accessed.
Connect the programming terminal to the system and run

the ReSource Software. Use the MONITOR I/O function to

display register 0 in DCS5000/AutoMax systems. In

AutoMate systems, use the POINT MONITOR function to

display the point. If the programmer is able to monitor the

inputs, the problem lies in the application software

(proceed to step 3). If the programmer cannot monitor the

inputs, the problem lies in the hardware (proceed to

step 4).

Step 3.

Verify that the user application program is correct.
This module cannot be written to. If a BASIC task caused

the bus error, the error log will contain the statement

number in the task where the error occurred. If a Ladder

Logic or Control Block task caused the error, you will need

to search the task for any instances where you used an

input as a ladder logic coil or wrote to it in a control block

task.
In AutoMate systems, search the task for any instances

where you used an input as a coil.

Step 4.

Verify that the hardware is working correctly.
Verify the hardware functionality by systematically

swapping out the input module, Processor module(s), and

backplane. If the problem is not corrected after each

swap, replace the original item before swapping out the

next item.
For remote I/O installations (DCS5000/AutoMax systems

only), systematically swap out the input module, the slave

remote module, and the backplane. After each swap, if the

problem is not corrected, replace the original item before

swapping out the next item.