AB Quality ALLEN-BRADLEY 1791 User Manual page 42

Chapter 4
Analog Block Applications Using
Block Transfers
4-2
Table 4.A
Bit/Word Descriptions for Block Transfer Read Instruction
Decimal Bit
Word
(Octal Bit)
Bits 15 (17)
Bit 14 (16)
Bit 13 (15)
Bits 08 12
(10 14)
Word 0
Bits 04 07
Bits 00 03
Bits 00 15
Word 1
(00 17)
Bits 00 15
Word 2
(00 17)
Bits 00 15
Word 3
(00 17)
Bits 00 15
Word 4
(00 17)
Power up (PU) status bit. This bit is set (1) if the module has not been
configured since the last power up. It is reset (0) when at least one valid BTW
has occurred since power up. Outputs are not enabled until the PU bit is reset.
Bad configuration (BC) bit. This bit is set (1) if an invalid configuration data has
been received, and the previous configuration remains in effect.
Out of range (OR) bit. When set, indicates one or both of the outputs has
received a value which exceeds the output range. Outputs are clamped at their
maximum or minimum values depending on the direction of the out of range
value.
Status Codes. When the Bad Configuration (BC) bit 14 (16), is set (1), the
status code indicates the following:
1 output channel 0 scaling error
2 output channel 1 scaling error
3 input channel 0 scaling error
4 input channel 1 scaling error
5 input channel 2 scaling error
6 input channel 3 scaling error
7 channel 0 alarm error
8 channel 1 alarm error
9 channel 2 alarm error
A channel 3 alarm error
When the output out of range (OR) bit 13 (15) is set (1), the status code bits
indicate the following:
Bit 08 (10) output 0 has been clamped at its minimum
Bit 09 (11) output 1 has been clamped at its minimum
Bit 10 (12) output 0 has been clamped at its maximum
Bit 11 (13) output 1 has been clamped at its maximum
High alarm bits. Set (1) if the input channel value is greater than the
corresponding high alarm value.
Bit 04 high alarm bit for channel 0
Bit 05 high alarm bit for channel 1
Bit 06 high alarm bit for channel 2
Bit 07 high alarm bit for channel 3
Low alarm bits. Set (1) if the input channel value is less than the corresponding
low alarm value.
Bit 00 low alarm bit for channel 0
Bit 01 low alarm bit for channel 1
Bit 02 low alarm bit for channel 2
Bit 03 low alarm bit for channel 3
Input data for channel 0.
Input data for channel 1.
Input data for channel 2.
Input data for channel 3.
Description