Rockwell Automation 1766-Lxxxx MicroLogix 1400 Programmable Controllers User Manual - Manual (Page 267)

Rockwell Automation Publication 1766-UM001H-EN-P - May 2014 227
MicroLogix 1400 Distributed Network Protocol (DNP3) Appendix F
Function Codes
FC_CONFIRM (FC Byte = 0x00)
00 - Confirm
A DNP3 master sends a message with this function code to confirm receipt of a
response fragment. In a general environment, the MicroLogix 1400 receives a
response with this function code. But the MicroLogix 1400 may generate a
response with this function code when a DNP3 Master sends a request with the
CON bit set in the application control header.
FC_READ (FC Byte = 0x01)
01 - Read
The READ function code is used by a DNP3 master to request data from the
MicroLogix 1400.
FC_WRITE (FC Byte = 0x02)
02 - Write
The WRITE function code is used to write the contents of DNP3 objects from
the DNP3 master to the MicroLogix 1400. This function code is used for
clearing bit IIN1.7 [DEVICE_RESTART], setting time in the MicroLogix 1400
and downloading user programs to the MicroLogix 1400 controller.
FC_SELECT (FC Byte = 0x03)
03 - Select
The SELECT function code is used in conjunction with the OPERATE
function code as part of select-before-operate method for issuing control
requests. This procedure is used for controlling binary output (CROB) or analog
output (AOB) objects.
FC_OPERATE (FC Byte = 0x04)
04 - Operate
See the comment for FC_SELECT (FC Byte = 0x03) on page 227.
FC_DIRECT_OPERATE (FC Byte = 0x05)
05 - Direct Operate