SJ700-2 Instruction Manual NT204DX - Hitachi America, Ltd.

Chapter 4 Explanation of Functions
4.2.77 Window comparators (WCO/WCOI/WCO2) (detection of terminal disconnection:
ODc/OIDc/O2Dc)
Related code
C021 to C025: Terminal [11] to terminal [15] functions
- The window comparator function outputs C026: Alarm relay terminal function
b060/b063/b066: Maximum-limit level of window comparators O/OI/O2
signals when the values of analog inputs O, b061/b064/b067: Minimum-limit level of window comparators O/OI/O2
OI, and O2 are within the maximum and
minimum limits specified for the window comparator. You can monitor analog inputs with reference to
arbitrary levels (to find input terminal disconnection and other errors).
- You can specify a hysteresis width for the maximum-limit and minimum-limit levels of the window
comparator.
- You can specify limit levels and a hysteresis width individually for analog inputs O, OI, and O2.
- You can fix the analog input data to be applied to an arbitrary value when WCO, WCOI, or WCO2 is
output. For this purpose, specify a desired value as the operation level at O/OI/O2 disconnection
(b070/b071/b072). When "no" is specified, the analog input data is reflected as input.
- Output values of ODc, OIDc, and O2Dc are the same as those of WCO, WCOI, and WCO2, respectively.
Item
Terminal [11] to terminal
[15] functions
Alarm relay terminal
function
Maximum-limit level of
window comparators
O/OI/O2
Minimum-limit level of
window comparators
O/OI/O2
Hysteresis width of
window comparators
O/OI/O2
Operation level at
O/OI/O2 disconnection
Function
code
C021-C025
C026
b060 (O )
b063 (OI)
b066 (O2)
b061 (O )
b064 (OI)
b067 (O2)
b062 (O )
b065 (OI)
b068 (O2)
b070 (O )
b071 (OI)
b072 (O2)
Range of data
Description
27
ODc: Detection of analog input O
disconnection
28
OIDc: Detection of analog input OI
disconnection
29
O2Dc: Detection of analog input O2
disconnection
54 WCO: Window comparator O
55 WCOI: Window comparator OI
56 WCO2: Window comparator O2
"Minimum-limit level + hysteresis width*2
(minimum of 0)" to 100. (%)
"Minimum-limit level + hysteresis width*2
Setting of maximum-limit level
(minimum of -100)" to 100. (%)
0 to "maximum-limit level - hysteresis
width*2 (maximum of 100)" (%)
-100 to "maximum-limit level - hysteresis
Setting of minimum-limit level
width*2 (maximum of 100)" (%)
Setting of hysteresis width for
0 to "(maximum-limit level - minimum-limit
maximum-limit and minimum-limit
level)/2 (maximum of 10)" (%)
levels
0 to 100 (%) or "no" (ignore)
Setting of the analog input value to be
applied when WCO, WCOI, or WCO2
-100 to 100 (%) or "no" (ignore)
(ODc, OIDc, or O2Dc) is output.
O, OI, or O2
Max(100%)
Hysteresis width
(b062,b065,b068)
Maximum-limit level of window
comparator (b061/b064/b067)
Applied analog data
Analog operation level at
disconnection (b070/b071/b072)
Min(O/OI:0%)
(O2 :-100%)
Applied analog data
Minimum-limit level of window
comparator (b060/b063/b066)
WCO/WCOI/WCO2
ODc/OIDc/O2Dc
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