Inovance H3U Series - REF Input;Output Refreshing

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4
4 Instructions 4.9.6 Refreshing
REF: Input/Output refreshing
◆
Overview
The REF instruction refreshes the input or output image storage area immediately.
REF S n
Input/Output
refreshing
Applicable model:
H3U
S
Bit element
head address
Head address of input or output bit elements to be
refreshed
16-bit instruction
(5 steps)
REF: Continuous
execution
REFP: Pulse
execution
n
Bit element
count
Number of input or output bit elements to be refreshed
◆
Operands
Operand
Bit Element Word Element
System·User System·User Bit Designation Indexed Address Constant
Real
Number
S X Y M T C S SM D R T C SD KnX KnY KnM KnS KnSM
V,Z
Modication K H E
n X Y M T C S SM D R T C SD KnX KnY KnM KnS KnSM
V,Z
Modication K H E
Note: The elements in gray background are supported.
◆
Function
The statuses of n elements from head address S are refreshed immediately. The following requirements
are posed because of PLC's byte-based port access feature:
The address S must be a element number whose lowest bit is 0, such as X0, X10, ……Y0, and Y10.
The value of n must be a multiple of 8 (in the range 8 to 256).
In normal cases, the status of the input port X is read before a program executes scanning, and the status
of the output port Y is refreshed in batches after scanning is completed (END is reached). This causes
an I/O delay. Use the REF instruction if you need to input the latest information to applications or output
operation results immediately.
• The REF instruction can be executed between the FOR and NEXT instructions and between CJ instructions.
• The REF instruction can be used to refresh the input and output of an interrupt subprogram to acquire the latest
input information and promptly output operation results.
• The actual change delay of the input port status depends on the lter time of input elements. X0 to X7 have the
digital lter function. The lter time is congurable (using the FNC51 REFF instruction) within the range 0 ms to 60
ms. Other I/O ports use hardware lter with a lter time of about 10 ms. For details about related parameters, see
the
User Guide – H3U Series Programmable Logic Controller (PLC) – Higher Performance & Pulse Motion
Contro
l. (Please visit http://www.inovance.cn/es to obtain the latest version.)
• The actual change delay of the output port status depends on the response time of output elements (for example,
relays). The output contacts involved in output refresh will act after the response time of output relays (transistors)
has elapsed. The response delay of the relay output type is about 10 ms (max.: 20 ms), that of the high-speed
output ports of the transistor output type is about 10 µs, and that of the output ports of general points is about 0.5
ms. For details about related parameters, see the
User Guide – H3U Series Programmable Logic Controller
(PLC) – Higher Performance & Pulse Motion Control
. (Please visit http://www.inovance.cn/es to obtain the
latest version.)