Combination Of Index Modification; Precautions - Mitsubishi Electric MELSEC iQ-R-R00CPU User Manual

Combination of index modification

This section describes the combination of index modification.
Modification order for the device specification and index modification
According to the priority order shown below, the device specification (digit specification, bit specification, indirect specification)
and index modification can be applied. However, some word devices may not follow the priority order shown below.
Order of priority When the device targeted for the device specification
and index modification is the bit device
High 1: Index modification

2: Digit specification

Low
Specification method combined with device specification
The device targeted for specification is modified in order of: 1st modification, 2nd modification and then 3rd modification.
Besides, the following contents can be used only for the device for which the 1st modification can be applied. (For example,
index modification + digit specification is impossible for the function input (FX).)
Device targeted for 1st modification
specification
Bit device Index modification
Word device Index modification
Index modification
Bit specification
Indirect Specification
Index modification
Indirect Specification

Precautions

This section describes the precautions on using index modification.
Index modification between the FOR and NEXT instructions
Between the FOR instruction and the NEXT instruction, pulse output is provided through the edge relay (V). However, pulse
output by the PLS, PLF, or pulse conversion (P) instruction is not available ( Page 337 Edge relay (V))
Index modification by the CALL instruction
In the CALL instruction, pulse output is provided through the edge relay (V). However, pulse output by the PLS, PLF, or pulse
conversion (P) instruction is not available ( Page 337 Edge relay (V))
Device range check for index modification
For details on the device range check when index modification is performed, refer to the following.
 MELSEC iQ-R Programming Manual (CPU Module Instructions, Standard Functions/Function Blocks)
When the device targeted for the device specification
and index modification is the word device
1: Index modification
2: Indirect specification
3: Bit specification
2nd modification 3rd modification
Digit specification 

Bit specification

Indirect Specification

Index modification

Bit specification
Indirect Specification Bit specification
Bit specification Index modification
Example
K4M100Z2
D10Z2.0
@D10Z2
D10.8Z2
@D10.8
@D10Z2.8
@D10.8Z2
21 DEVICES
355
21.8 Index Register (Z/LZ)
21