Window Comparators (Wc) (Detection Of Terminal Disconnection:dc) - Hitachi NES1-004SB Quick Reference Manual

7.8.21 Window comparators (WC) (detection of terminal disconnection:Dc)

- The window comparator function outputs signals when the values of analog inputs O/OI is 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.
- You can fix the analog input data to be applied to an arbitrary value when WC is output. For this purpose,
specify a desired value as the operation level at O/OI disconnection (b070). When "no" is specified, the
analog input data is reflected as input.
- Output values of Dc is the same as those of WC respectively.
Item
Terminal [11] functions
Alarm relay terminal
function
Maximum-limit level of
window comparators O/OI
Minimum-limit level of
window comparators O/OI
Hysteresis width of window
comparators O/OI
Operation level at O/OI
disconnection
O/OI input
Max(100%)
Min(0%)
WC output
Dc output
Function
code
C021
C026
"Minimum-limit level + hysteresis width*2
b060
(minimum of 0)" to 100. (%)
0 to "maximum-limit level - hysteresis
b061
width*2 (maximum of 100)" (%)
0 to "(maximum-limit level - minimum-limit
b062
level)/2 (maximum of 10)" (%)
b070 0 to 100 (%) or "no" (ignore)
Hysteresis width
(b062)
Applied analog data
Analog input data
Chapter 7 Explanation of Functions
Range of data
27
54
7 - 75
Description
Dc: Detection of analog input
disconnection
WC: Window comparator
Setting of maximum-limit level
Setting of minimum-limit level
Setting of hysteresis width for
maximum-limit and minimum-limit levels
Setting of the analog input value to be
applied when WC (Dc) is output.
Maximum-limit level of window
comparator (b061)
Analog operation level at
disconnection (b070)
Minimum-limit level of window
comparator (b060)