Rockwell Automation 1791-XXXX ANALOG BLOCK I/O - Manual (Page 44)

Analog Block Applications Using
Block Transfers
Chapter 4
4-4
The bit/word descriptions are shown in Table 4.B.
Table 4.B
Bit/Word Descriptions for the Block Transfer Write Instruction
Word
Decimal Bit
(Octal Bit)
Description
Module Mode. Bits 12Ć15 (14Ć17) determine the operation of the block module.
Bit 15 (17) 14 (16) 13 (15) 12 (14)
Bits 12Ć15 (14Ć17)
0 0 0 0 Normal operation with voltage inputs
Bits 12Ć15 (14Ć17)
0 0 0 1 Normal operation with current inputs
1 1 0 0
Calibration operation (refer to
Chapter 7)
Scaler Mode
Bit 11 (13) 10 (12) Mode Binary Counts Ć binary data sent to the
outputs and returned from the inputs is
0 X binary
outputs and returned from the inputs is
calibrated, but not scaled, providing maximum
possible resolution
1 0 default
possible resolution.
User Scaling Ć the input and output data are
scaled by the values in words 3 thru 6 for
1 1 user
scaled by the values in words 3 thru 6 for
outputs, and words 7 thru 14 for inputs.
Default Scaling Values are shown below:
Module
Range
Default Default Approximate
Bits 10Ć11 (12Ć13)
Module
Mode
Bit 12 (14)
Bit 09
(11)
Bit 08
(10)
Default
Minimum
Default
Maximum
Approximate
Default Resolution
0 0 0 Ć10000 +10000 14 Bits
0 0 1 Ć5000 +5000 13 Bits
Word 0
1 0 1 Ć20000 +20000 14 Bits
Word 0
0 1 0 0000 +10000 13 Bits
0 1 1 0000 +5000 12 Bits
1 1 1 0000 +20000 14 Bits
Default scaling for the output is determined by the catalog number as follows:
Catalog Number
Default
Minimum
Default
Maximum
Approximate
Default Resolution
1791ĆN4V2, ĆNDV Ć10000 +10000 14 Bits
1791ĆN4C2, ĆNDC 00000 +20000 13 Bits
Range selection bits. Bit 08 selects voltage and bit 09 selects unipolar or bipolar.
Bit
Range
Bits 08Ć09 (10Ć11) 09 (11) 08 (10)
Range
( )
0 0 +10V
0 1 +5V
1 0 0Ć10
1 1 0Ć5
Bits 04Ć07
Alarm Enable bits. Enables input alarm when set (1). Bit 04 corresponds to channel 0, bit 05
corresponds to channel 1, bit 06 corresponds to channel 2 and bit 07 corresponds to
channel 3.
Bits 00Ć03 Digital Filter selection. Default of 0000 selects No Filter. Refer to Table 4.C.