Allen-Bradley FLEX I/O 1794-ID2, Руководство пользователя, Страница: 47 / 84

4–5 Writing Configuration to and Reading Status from Your Module with a Remote I/O Adapter
Publication 1794-6.5.15 – December 1998
Block Transfer Write Word Assignments for the Incremental
Encoder Module
(Octal Bit)
⇒
17 16 15 14 13 12 11 10 07 06 05 04 03 02 01 00
Dec. Bit
⇒
15 14 13 12 11 10 09 08 07 06 05 04 03 02 01 00
Word
⇓
Write
0 Channel 0 Control Word – Sets the function of counter 0
1 Channel 1 Control Word – Sets the function of counter 1
2 Channel 0 Preset – value to load or compare with counter 0
3 Channel 1 Preset – value to load or compare with counter 1
Bit/Word Definitions for the Block Transfer Write Words for the
Incremental Encoder Module
Write
Word Bit
Definition
Write
Wor 0
0–15 (0–17) Channel 0 Control Word – Control word for setting the function of counter 0.
Word 0
Bits 00–02 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 (Reset) bit – A positive edge on this bit moves the value in Preset X to Counter X, independent of Preset
Enable. NOTE: To use Preset as Reset, use a count value of 0000 in the Preset value word.
Bit 04 Enable Z Preset bit – When this bit is set (1), a positive edge on Z preloads Counter X = Preset X, independent of
Cal Enable. NOTE: If Z is configured to do Store and Preset (Reset), the Store will occur first.
Bit 05 Count Enable bit – When this is set (1), the incremental encoder is enabled.
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 The counter can be calibrated when G is high (active).
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