Allen-Bradley FLEX I/O 1794-ID2, Руководство пользователя, Страница: 18 / 84

1–8 Overview of the Incremental Encoder Module
Publication 1794-6.5.15 – December 1998
Store Function
Use the store function to copy the value in the counter register
(Counter) to the latch register (StoreValue).
The StoreControl parameter determines the store function. Execution
occurs on either the positive or negative edge of input signals G and
Z respectively (see table). The parameter is a 2–bit binary code in
write word 1 (bits 11 and 12)
Word
1 or 2
Bits
11–12
Binary 12 11 Store Control bits
1 or 2 11–12
0 0 0 Save the counter value on the positive edge of Z
(if Stored X = 0)
1 0 1 Save the counter value on the positive edge of G
(if Stored X = 0)
2 1 0 Save the counter value on the negative edge of G
(if Stored X = 0)
3 1 1 Save the counter value on both the positive edge
and negative edge of G (if Stored X = 0)
The parameter Stored must be reset (0). Stored is set (1) when the
operation is completed. Reset after the operation with StoreReset.
Store Control = 1
Counter Register
Logic
G
Stored = 0
The counter value is copied to the store register on the positive edge of input signal G.
Example
Store Register
Latched = 1
Limitation Function
If the control bit RangeLimited = 1, the counter counts up to the
preset value and restarts at 0. Counting down, the counter reaches the
preset value on the next pulse if the current counter value = 0.
RangeLimited = 0 corresponds to RangeLimited = 1 if the preset
value = FFFF in hex = 65535 in decimal.
The flag PresetReached is set when the counter is equal to the preset
value. Use PresetReset to reset the flag.