Rockwell Automation 1794-ID2 U.MNL INCREMENTAL ENCODER User Manual
Page 59
5–7
How Communication Takes Place and I/O Image Table Mapping with the DeviceNet Adapter
Publication 1794ĆUM015B-EN-P - May 2001
Definition
Bit
Word
Write
Word 2
Channel 1 Control Word - Control word for setting the function of counter 1.
Word 2
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 incremental encoder 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
(11 12)
10 09 Gate Control bits
(11-12)
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 Latch Control bits
(13-14)
0
0 Save the counter value on the positive edge of Z (if Stored X = 0)
0
1 Save the counter value on the positive edge of G (if Stored X = 0)
1
0 Save the counter value on the negative edge of G (if Stored X = 0)
1
1 Save the counter value on the positive edge and negative edge of G (if Stored X = 0)
Bit 13 (15)
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 (16)
Store Reset bit - A positive edge on this bit resets Stored X in Signals.
Bit 15 (17)
Store Reset bit - A positive edge on this bit resets Preset Reached in Signals.
Write
Word 3
Bits 00-15
(00-17)
Preset 0 - Value to load or compare with counter 0
Write
Word 4
Bits 00-15
(00-17)
Preset 1 - Value to load or compare with counter 1