Delta Electronics Extension Digital I/O Module DOP-EXIO14RAE User Manual

Page 139

Appendix D Use of Application Instructions|DOP-EXIO Series

D-58

Revision March, 2008, Doc. Name: 2007PDD23000014

Mnemonic

Operands Function

REF

Refresh

Bit Devices

Word Devices

X Y M S K H

KnX

KnY

KnM KnS

Note:

1. D must designate X0, X10, Y0, Y10…the points whose 1s digit is “0”.

See remarks for more details.

2. Range of n: 8 ~ 256 (has to be the multiple of 8).

16-bit instruction (5 Steps)

REF

Continuous
execution

32-bit instruction

- -

Flags: None

Operands:

: Start device to be I/O refreshed

: Number of items to be I/O refreshed

Explanations:
1. The status of all input/output terminals of DOP-EXIO series will be updated after the program

scans to END. When the program starts to scan, the status of the external input terminal is read
and stored into the memory of the input point. The output terminal will send the content in the
output memory to the output device after END instruction is executed. Therefore, this instruction
is applicable when the latest input/output data are needed for the operation.

2. REF command can be used between FOR and NEXT instruction, and between CJ instructions.

If there is an interrupt occurs in the period of time when input/output terminals is working, REF
command can also be used. It can be also used to interrupt the subroutine program.

3. The

operand

should always be a multiple of 10, i.e. 00, 10, 20, 30… etc., so it should be X0,

X10, Y0, Y10… etc. The operand n hould always be a multiple of 8, i.e. 8, 16, 24, 32…etc. and
its available range is 8~256. If the value of n is out of the stated range (8~256) or not a multiple
of 8, an “operation error” will be generated.

Program Example 1:
When X0 = On, DOP-EXIO series will read the status of input points X0 ~ X7 immediately and refresh
the input signals without any input delay.

REF

K16

Program Example 2:
When X0 = On, the 8 output signal from Y0 ~ Y7 will be sent to output terminals and refreshed. But
there is 10ms input delay occurred on the input signals.

REF