UMAX180800, 20 Thermocouple, 2 RTD, 4 Inputs, 6 Relays Dual CAN Controller
Version 1
Page: 28-71
3
>=, True when Argument 1 is greater than Argument 2
4
<, True when Argument 1 is less than Argument 2
5
<=, True when Argument 1 is less than or equal Argument 2
6
OR, True when Argument 1 or Argument 2 is True
7
AND, True when Argument 1 and Argument 2 are True
Operator 1 and Operator 2 are configured to OR by default. The table above cannot be used
for comparing the conditions because they can only be compared with logical operators, which
are listed in Table 23.
Table 23. Condition Operator Options
Value
Meaning
0
OR, True when Argument 1 or Argument 2 is True
1
AND, True when Argument 1 and Argument 2 are True
2
XOR, True when Argument 1 is not equal to Argument 2
If only one condition is used, it is to make sure that Operator 3 is set to
OR
so that the result is
based solely on the condition which has been chosen.
3.9 Set / Reset Latch Function Block
Set-Reset Block
consists of only 2 control sources:
Reset Source
and
Set Source
. The
purpose of these blocks is to simulate a modified latching function in which the ‘Reset Signal’
has more precedence. The ‘latching’ function works as per the Table 24 below.
Table 24. Set-Reset Function block operation
‘Set Signal’ ‘Reset Signal’
‘Set-Reset Block Output’
(Initial State: OFF)
OFF
OFF
Latched State
OFF
ON
OFF
ON
OFF
ON
ON
ON
OFF
The
Reset
and
Set
sources have associated with them a minimum and maximum threshold
values which determine the ON and OFF state. For the
Reset Source
are
Reset Minimum
Threshold
and
Reset Maximum Threshold
. Similarly, for the
Set Source
are
Set Minimum
Threshold
and
Set Maximum Threshold
. These setpoints also allow to have a dead band in
between ON/OFF states and they are in terms of percentage of input selected.
As seen in Table 24
above, the ‘Reset Signal’ has more precedence over the ‘Set Signal’ - if
the state of ‘Reset Signal’ is
ON
, the state of ‘Set-Reset Block Output’ will be
OFF
. To create
an
ON
state in ‘Set-Reset Block Output’ the state of ‘Reset Signal’ must be
OFF
while the state
of ‘Set Signal’ is
ON
. In this case, the state of ‘Set-Reset Block Output’ will remain
ON
even if
‘Set Signal’ turns
OFF
as long as ‘Reset Signal’ remains
OFF.
As soon as the ‘Reset Signal’
turns
ON
the ‘Set-Reset Block Output’ will turn
OFF
regardless of the state of ‘Set Signal’.
3.10 Lookup Table Function Block
Lookup Tables are used to give output response up to 10 slopes per input. If more than 10
slopes are required, A Programmable Logic Block can be used to combine up to three tables
to get 30 slopes as described in Section 3.11.
