Rockwell Automation 1785-Vx0B, D17856.5.9 PLC-5 VME VMEbus Programmable Controllers User Manual - Manual (Page 74)

Chapter 6
PLC-5/VME Processor
Communications Commands
6-5
Use this command to debug or test PCCC transmission capability. The
command packet can contain up to 243 bytes of data. The processor
simply returns (“echos”) the same data in the reply packet.
Message Format
DATA DST
00
PSN
00
SRC
00
PSN
00
CMD
06
STS
00
TNS FNC
00
Command Packet
LNH
Hi
LNH
Lo
DST
00
PSN
00
SRC
00
PSN
00
CMD
46H
STS
Reply Packet
TNS
up to 243 bytes
SAME DATA
up to 243 bytes
Error Codes
Extended status codes are reported in the response packet. The STS byte
contains 00H if no error, F0H when the PLC-5/VME processor detects an
error. If an error, the error code is indicated in the EXT STS byte
as follows:
STS EXT STS Description
00H – No error
F0H 10H Illegal command or format
20H Host has a problem and will not communicate
30H Remote station host is missing, disconnected, or shut down
40H Host could not complete function due to hardware fault
50H Addressing problem or memory protect rungs
60H Function disallowed due to command protection selection
80H Compatibility mode file missing or communication zone problem
90H Remote station cannot buffer command
B0H Remote station problem due to download
Refer to page D-3 for additional information on PCCC status codes.
Sample API Module
For a sample
interface
header file: Refer to page: For a sample
implementation
source file: Refer to page:
P40VECHO.H B-58 P40VECHO.C B-59
Echo