Rice Lake Allen-Bradley Remote I/O - Manual (Page 12)

8 Remote I/O Installation and Programming Manual
3.2 Input Image Table Format
In response to a discrete command, the Remote I/O Interface interface returns data and status information across
the network as two 16-bit words. This information is read from the input image table by the PLC. The format of
the input image table is shown in Table 3-3:
Table 3-3. Input Image Table Format
Bit 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
Word 0 v15 v14 v13 v12 v11 v10 v09 v08 v07 v06 v05 v04 v03 v02 v01 v00
Word 1 s11 s10 s09 s08 s07 s06 s05 s04 s03 s02 s01 s00 v19 v18 v17 v16
where:
v00–v19 20-bit unsigned integer
s00–s11 Status data
Value
Weight data is returned to the PLC using word 0 and
bits 0 to 3 from word 1 of the input image table. The
PLC can use just word 0 to read data in a 16-bit
format, allowing unsigned values from 0 to 65,535 to
be returned from the indicator. If larger numbers or
greater precision is required, the PLC can piece
together the additional four bits from word 1, resulting
in a 20-bit unsigned value. This format allows the
indicator to return values up to 1,048,575. Polarity is
returned with status data. The weight data returned is
the displayed weight after the command is executed
unless the command specifies otherwise.
Status Data
Indicator status data is returned in bits 4–15 of word 1.
Status data is listed in Table 3-4. Batch commands
return batch status in place of bits 8–15 as listed in
Table 3-5.
Channel Bits
Bits s01–s03 of the indicator status data (Table 3-4)
are used to represent the lower three bits of the scale
channel number. For example, if a value of ‘001’ is
returned in these bits, the scale channel number is 1, 9,
17 or 25.
Table 3-4. Indicator Status Data Format
Word 1
Bit
Status
Bit
Indicator Status Data
Value=0 Value=1
04 s00 Positive weight Negative weight
05 s01 Lower three bits of scale number
06 s02
07 s03
08 s04 Gross Net
09 s05 No tare Tare acquired
10 s06 Primary units Secondary/ other
units
11 s07 Standstill In motion
12 s08 Weight invalid /
Over-range
Weight OK
13 s09 Not zero Center of zero
14 s10 Tare not entered Tare entered
15 s11 Error No error
Table 3-5. Batch Function Status Data Format
Word 1
Bit
Status
Bit
Batch Function Status Data
Value=0 Value=1
08 s04 Alarm OFF Alarm ON
09 s05 Batch not stopped Batch stopped
10 s06 Batch not running Batch running
11 s07 Batch not paused Batch paused
12 s08 Digital input 1 OFF Digital input 1 ON
13 s09 Digital input 2 OFF Digital input 2 ON
14 s10 Digital input 3 OFF Digital input 3 ON
15 s11 Digital input 4 OFF
( 520 ) Error
Digital input 4 ON
( 520 ) No error