2–13
How Communication Takes Place and I/O Image Table Mapping
Publication 17946.5.5 - October 1996
Definition
Decimal Bit
Word
Bits 00-07
Underrange bits (U)
for individual channels
(420mA current
input only)
- Bit 00 corresponds to input channel 0, bit 01
corresponds to input channel 1, and so on. When set (1),
indicates either a broken or open input wire, or input current
below 420mA.
Read Word 9
Bits 0814
Not used - set to 0.
Bit 15
Power Up bit - included in series B modules only. This bit
is 0 in series A modules. This bit is set to 1 when all bits in
the configuration register are 0 (unconfigured state).
The
configuration register can be cleared by either of the reset
inputs, or by the user writing all zeroes to it.
Write Word 1
Bits 00-07
Full range bits (F)
for individual channels - Bit 00 corresponds
to input channel 0, bit 01 corresponds to input channel 1, and
so on. Refer to range selection above.
Write Word 1
Bits 08-15
Configure select bits (C)
for individual channels - Bit 08
corresponds to input channel 0, bit 09 corresponds to input
channel 1, and so on. Refer to range selection above.
Write Word 2
Bits 00-15
Not used - set to 0.
Write Word 3
Bits 00-15
Not used - set to 0.
Write Word 4
Bits 00-15
Not used - set to 0.
Write Word 5
Bits 00-15
Not used - set to 0.
Write Word 6
Bits 00-15
Not used - set to 0.
4 Output Analog Module (1794OE4) Image Table Mapping
Module Image
I/O Image
Analog Data Channel 0
Analog Data Channel 1
Analog Data Channel 2
Analog Data Channel 3
Not used
Not used
Not used
Not used
Not used
Not used
Not used
Not used
Not used
Not used
Not used
Not used
Diagnostics
Config. Select
Full Range
Input Size
Output Size
0 or 1 Word
1 or 6 Words
Read
Write
OE
PU