7.8 Connections with MELSEC
7-39
7
7.8.3 Programming
218IFA Programming Suggestions
The 218IFA communicates with the MELSEC Controller that performs Extended MEMO-
BUS and MELSEC message conversion processing. Thus there is no need for the MELSEC
message configuration to be recognized by the user application. The user can easily commu-
nicate with the MELSEC Controller by using the MSG-SND function to specify MELSEC
under Protocol Type in the 218IFA Connection Parameter Window.
Refer to the list of MELSEC commands for the commands that are used by the MSG-SND
function, and the MEMOBUS commands corresponding to the MELSEC commands.
For example, MEMOBUS command 01 or 02 will correspond to MELSEC command 00
(reads bit devices in 1-bit units).
MELSEC Programs
The Ethernet Module (AJ71E71) must be initialized by the MELSEC ladder logic program.
Refer to the procedure for refreshing other nodes in the MELSEC manual, and create a lad-
der logic program for initial processing.
7.8.4 MELSEC Commands
The following table shows the common MELSEC ACPU commands that are supported by
the MP900-Series 218IFA Module, and the corresponding MEMOBUS command numbers.
Table 7.8 Common MELSEC ACPU Commands
Command Description Qty 218IFA
Support
*
MEMOBUS
Command
00H Reads bit devices in 1-point units
256 points Yes 01H/02H
01H Reads bit devices in 16-point units
128 words
(2,048 points)
No −
Reads word devices in 1-point units
256 points Yes 03H/04H/
09H/0AH
02H Writes bit devices in 1-point units
256 points Yes 05H/0FH
03H Writes bit devices in 16-point units
40 words
(640 points)
No −
Writes word devices in 1-point units
256 points Yes 06H/0BH/10H
04H Randomly specifies, sets, and resets bit devices and device
numbers in 1-point units
80 points No −
05H Randomly specifies, sets, and resets bit devices and device
numbers in 16-point units
40 words
(640 points)
No −
Randomly specifies, sets, and resets word devices and device
numbers in 1-point units
40 points Yes 0EH
06H Sets the bit devices to be monitored in 1-point units
40 points No −
To Next Page
Loading...
