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Chapter 4. Ladder Diagram (LD) Programming
Command Block Structure
Address
Data Block Length
(in words)
Address + 1
Wait/No Wait Flag
Address + 2
Status Pointer
Memory Type
Address + 3
Status Pointer Offset The word at address + 3 contains the offset for the status word
Address + 4
Idle Timeout Value
Address + 5
Maximum
Communication Time
Address + 6
Data Block
to Address + 133
Status Pointer Memory Type
Status pointer memory type contains a numeric code that specifies the user reference memory type
for the status word. The table below shows the code for each reference type:
For this memory type
%I
Discrete input table (BIT mode)
%Q
Discrete output table (BIT mode)
%I
Discrete input table (BYTE mode)
%Q
Discrete output table (BYTE mode)
%R
Register memory
%W
Word memory
%AI
Analog input table
%AQ
Analog output table
Notes:
The value entered determines the mode. For example, if you enter the %I bit mode is 70, then the
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offset will be viewed as that bit. On the other hand, if the %I value is 16, then the offset will be
viewed as that byte.
The high byte at address + 2 should contain zero.
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152
PACSystems* RX7i, RX3i and RSTi-EP CPU Programmer's Reference Manual
The number of data words starting with the data at address+6 to the
end of the command block, inclusive. The data block length ranges
from 1 to 128 words. Each COMMREQ command has its own data
block length. When entering the data block length, you must ensure
that the command block fits within the register limits
Must be set to 0 (No Wait)
Specifies the memory type for the location where the COMMREQ
status word (CSR) returned by the device will be written when the
COMMREQ completes.
within the selected memory type.
Note:
The status pointer offset is a zero-based value. For example,
%R00001is at offset zero in the register table.
This parameter is ignored in No Wait mode.
This parameter is ignored in No Wait mode.
The data block contains the command's parameters. The data block
begins with a command number in address + 6, which identifies the
type of communications function to be performed. Refer to the
specific device manual for COMMREQ command formats.
Enter this decimal value
70
72
16
18
8
196
10
12
GFK-2950C
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