Allen-Bradley FLEX I/O 1794-ID2, User Manual, Page: 69 / 84

6–11 Input, Output and Configuration Files for Analog Modules when used with ControlNet
Publication 1794-6.5.15 – December 1998
Definition
Bit Configuration
Word
Word 1 Channel 1 Control Word – Control word for setting the function of counter 1.
Bits 00–02 Bit 02 01 00 Mode Selection bits
0 0 0 Counting on positive (rising) edge of input signal A. (Up/dwn counting determined
by B.)
0 0 1 Quadrature encoder X1
0 1 0 Quadrature encoder X2
0 1 1 Quadrature encoder X4
1 0 0 Counting up on the positive edge of input signal A, and down on positive edge of
input signal B.
1 0 1 No count function.
1 1 0 No count function.
1 1 1 No count function.
Bit 03 Preset bit – A positive edge on this bit moves the value in Preset X to Counter X, independent of Preset
Enable.
Bit 04 Preset Enable bit – When this bit is set (1), a positive edge on Z preloads Counter X = Preset X,
independent of Cal Enable.
Bit 05 Count Enable bit – When this is set (1), the pulse counter is counting.
Bits 06–08
06–10
Calibration Control bits – bits 06, 07 and 08
(06–10)
06 Enable bit – When this bit is set (1), the counter can be calibrated.
07 Direction bit – When this bit set (1), calibration is performed in a negative direction; when reset (0),
calibration is performed in a positive direction.
08 Reset bit – Calibration is acknowledged and a new calibration is enabled on a positive edge on this
bit.
Bits 09–10 10 09 Gate Control bits
0 0 No gate function on input G
0 1 Counting only if G is high (active)
1 0 Counting only if G is low (inactive)
1 1 Calibration if G is high (active) and ???
Bits 11–12
(13–14)
12 11 Store Control bits – These bits will trigger a Store only if the channel Store status bit (L0 or L1)
is cleared (0).
13–14
0 0 Save the counter value on the positive edge of Z (if Store X = 0)
0 1 Save the counter value on the positive edge of G (if Store X = 0)
1 0 Save the counter value on the negative edge of G (if Store X = 0)
1 1 Save the counter value on the positive edge and negative edge of G (if Store X = 0)
Bit 13 Rollover bit – When set (1), the counter counts up to the preset and then restarts at 0. If this bit is reset (0)
(not rollover), the rollover preset value = FFFF (hex = 65535 (decimal).
Bit 14 Store Reset bit – A positive edge on this bit resets Store X in Signals.
Bit 15 Store Reset bit – A positive edge on this bit resets Preset Detected in Signals.
Word 2 Bits 00–15 Preset 0 – Value to load or compare with counter 0
Word 3 Bits 00–15 Preset 1 – Value to load or compare with counter 1
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