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Message completion and status bits – Rockwell Automation 1785-Vx0B, D17856.5.9 PLC-5 VME VMEbus Programmable Controllers User Manual User Manual

Page 53

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Chapter 4

Ladder-Program Interfaces

4-6

The PLC-5/VME processor manipulates only two of the status bits in the
control word of the internal message control block:

DN

(done)

ER

(error)

For the copy operations, DN is not set until and unless the data are
successfully transferred. If an error occurs, ER is set and an error code is
placed in the message control block.

For the SVI operation, DN is set if and when the interrupt-acknowledge
cycle is successfully performed by the interrupt handler. If the message
syntax is incorrect (interrupt is not 1-7 or status/ID is not two hexadecimal
digits), ER is set along with an error code. For the CSF operation, DN is
set immediately.

For unrecognizable messages, ER is set along with an error code. The
error codes are:

Code

Explanation

0000H

Success

0001H

Invalid ASCII message format

0002H

Invalid file type

0003H

invalid file number

0004H

Invalid file element

0005H

Invalid VME address

0006H

Invalid VME transfer width

0007H

Invalid number of elements requested for transfer

0008H

Invalid VME interrupt level

0009H

Invalid VME interrupt status-id value

000AH

VMEbus transfer error (bus error)

000BH

Unable to assert requested interrupt (already pending)

000CH

Raw data transfer setup error

000DH

Raw data transfer crash (PLC switched out of run mode)

000EH

Unknown message type (message type not ASCII)

If the PLC-5/VME processor receives the same message control block with
the same msg_address field from the processor core with the .TO (timeout)
bit set, the current operation is terminated.

Message Completion and
Status Bits