4-10 Series 90-30/20/Micro Programmable Controllers Reference Manual – September 1998 GFK-0467K
4
The control word stores the state of the boolean inputs and outputs of its associated function block,
as shown in the following format:
15
14
13
12
11
10
9
8
6
5
4
3
2
1
0
Q (counter/timer
status output)
EN (enable input)
Enable input,
Reset input
Reserved
Reserved
7
Bits 0 through 11 are used for timer accuracy; bits 0 through 11 are not used for counters.
Note
Use care if you use the same address for PV as the second word in the block of
three words. If PV is not a constant, the PV is normally set to a different location
than the second word. Some applications choose to use the second word address
for the PV, such as using %R0102 when the bottom data block starts at %R0101.
This allows an application to change the PV while the timer or counter is running.
Applications can read the first CV or third Control words, but the application
cannot write to these values, or the function will not work.
Special Note on Certain Bit Operations
When using the Bit Test, Bit Set, Bit Clear or Bit Position function, the bits
are numbered 1 through 16, NOT 0 through 15 as shown above.