Omron PRT1-COM Operation Manual page 154

Counter Units
BCD (Data Code Switching Bit OFF)
Set the output conditions with 3 bits.
000: Present value ≥ Set value → Output ON
Not 000: Present value ≤ Set value → Output ON
(Whether output is actually made depends on the settings
of the External Output Enable Bits, word n+2 bits 08, 09)
Set the sign with 1 bit.
0: Positive
1: Negative
Hexadecimal (Data Code Switching Bit ON)
Set the output conditions with 3 bits.
000: Present value ≥ Set value → Output ON
Not 000: Present value ≤ Set value → Output ON
(Whether output is actually made depends on the settings of
the External Output Enable Bits, word n+2 bits 08, 09)
Word Functions
144
3. Setting of the set values can be performed regardless of whether or not
count operation is being carried out. Due to the communications time
required for remote I/O communications, however, timing for setting cannot
be made with perfect accuracy during count operation.
Word n+1
Word n+1
Reading Set Values 1 and 2
By switching ON the Set Value 1 Reading Bit (word n+2, bit 04) or the Set Value 2
Reading Bit (word n+2, bit 05), the set values can be read and stored in words m,
m+1 of the input area. When this is performed, the set output conditions will also
be read. The format of the stored value will be the same as that at setting.
Note The values will be stored in either BCD or hexadecimal, according to the setting
of the Data Code Switching Bit (word n+2, bit 03).
The Counter Unit is allocated output word 3 and input word 3 in the allocated
area of the Master. Readings of the settings and status of the Counter Unit are
made from the Master via this area.
This section describes the functions of the words that the Counter Unit uses.
In the following explanation, word n refers to the first word in the output area, and
m word refers to the first word in the input area.
Note 1. For details about allocation in the allocation area in the Master, refer to the
PROFIBUS-DP Master Operation Manual (W349).
2. If the power supply from the I/O unit interface to the Counter Unit stops, the
Counter Unit will stop count operations. If this happens, it will be necessary
to start up the Counter Unit again. Furthermore, when this is carried out, the
present value, the set values, and the count modes will all be cleared and so
these settings will also have to be made again.
Word n
Word n+2
When setting negative numbers, use the 24 bit 2's com-
plement (the last 24 bits of the 32 bit 2's complement).
Example: To set --10,000
--10,000 (decimal) → FFFF D8F0 Hex (32-bit 2's com-
plement) → FF D8F0 Hex (24-bit 2's complement)
Section 7-3