Rockwell Automation 61C351 2-In/2-Out 4-20 mA Analog Rail Module User Manual

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4Ć9

For processors that do not support the AIN and AOUTblocks, you

can use the MOVE block to move data in and out of the registers

assigned. OverĆrange and underĆrange bits should be used as

inputs to error coils. The I/O update will occur automatically at the

end of each scan. See Appendix C for a sample AutoMate program

that writes to and reads from the Analog Rail module without using

AIN and AOUTblocks.

4.1.4

Analog In (AIN) and Analog Out (AOUT) Instruction

Blocks

The AIN and AOUT blocks are used, respectively, to read inputs

from and write outputs to the Analog Rail module. AIN and AOUT

blocks are supported for the 20E processor. The AIN and AOUT

blocks make it possible to update the channels on the Analog Rail

module during the scan instead of at the end of the scan (the

standard AutoMate I/O update). The blocks also make it possible to

update all four channels during the scan in Rail mode, a hardware

configuration which would otherwise allow only one channel on the

module to be updated. The format of the two blocks is shown in

figures 4.11 and 4.12.

AIN Instruction Block

The example below shows an AIN block for an Analog Rail module connected to

port 2 of an AutoMate Processor.

IOPORTĆ Processor port to which the Analog Rail is connected (directly or

indirectly); value range 0Ć3.

LHPORTĆ Local I/O Head port to which the Analog Rail is connected; value

range 0Ć3. If a Local I/O Head is not used, the value is 0.

CHAN Ć

Channels on the Analog Rail module to read; value range 2 or 3.

DESTĆ

.01

AIN

[ ]

AIN

IOPORT:

LHPORT:

CHAN:

DEST:

VALUE:

2000

AutoMate 20E

with ports

0, 1, 2, and 3

Analog Rail with

channels 0, 1, 2, and 3

In Rail Mode

Chan 0

Chan 1

Chan 2

Chan 3

.01

( )

.00

( )

Figure 4.11 Ć AIN Instruction Block