Flags; Precautions When Executing Iord Instruction; Iord Program Example - Omron SYSMAC CS1G Operation Manual

IORD Instruction to Transfer Data
5-3-3

Flags

Name Symbol
Error Flag ER
Equals Flag =
5-3-4

Precautions when Executing IORD Instruction

5-3-5

IORD Program Example

212
ON
• The No. of transferred words in D is not
between 0000 and 0008 Hex.
• The unit number data in D is not between 8000
and 800F Hex.
• The specified CPU Bus Unit does not support
the IORD instruction.
• The specified Unit has a setting error or unit
error.
• The read position data was not in the specified
format or not within acceptable range.
• The specified MC Unit address does not exist.
• The specified No. of position data words trans-
ferred was not a multiple of two.
• The specified No. of system parameter words
transferred was not a multiple of two.
• The value of the MC Unit address plus the
number of transferred words divided by 2
exceeded 27FF Hex (upper position data limit
10240).
• More than 8 words were specified for position
data transfer.
• The IORD instruction was completed success-
fully.
When transferring the data by IORD instruction, make sure to transfer the
data with the total number of transferred words (2 to 8 words). Do not start or
end transferring the data in the middle of the data. Doing so will turn ON the
ER flag.
This section provides a detailed example of data transfer when the MC Unit is
mounted on a CS-series PLC and the unit number is set to zero. In this exam-
ple, it is assumed that operands in the IORD and the transferred data are cor-
rect.
When debugging, create a ladder program that refers to the ER flag or the
[Alarm] bit (n+12 words bit 00).
Example 1) Read four position data (PL0456 to PL0459 Hex) in the MC Unit
to the D00100 toD00107.
Position data to be read
PL0456 4567890
PL0457 12345678
− 38765432 →
PL0458
PL0459 123456
• The conditions other than the ones
described on the left.
• The IORD instruction was not com-
pleted normally.
• A previous transfer has not been com-
pleted.
Destination address
→
D00100 to D00101
→
D00102 to D00103
D00104 to D00105
→
D00106 to D00107
Section 5-3
OFF