Inputs, Outputs, Internal Variables, Counters; Limit Thresholds; Boolean Logic - LOVATO ELECTRIC DMG800 Manuel D'application

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INPUTS, OUTPUTS, INTERN L V RI BLES, COUNTERS, N LOG INPUTS
– The inputs and outputs of the expansion modules are identified by a code and a sequence number. For instance, the digital inputs are identified by code INPx,
where x is the number of the input. In the same way, digital outputs are identified by code OUTx.
– The sequence number of I/Os is simply based on their mounting position, with a progressive numbering from left to right. For instance the input INP1 is the
input terminal closest to the base unit, while the subsequent inputs will be named INP2, INP3 and so on.
– The DMG800 supports a maximum of 8 digital inputs and 8 outputs that will thus be numbered INP1...8 and OUT1...8. For every I/O, there is a dedicated
setting menu that allows to specify functionality and properties.
– In a similar way, there are some internal bit-variables (markers) that can be associated to the outputs or combined between them. For instance, it is possible
to apply some limit thresholds to the measurements done by the multimeter (voltage, current, power, etc.). In this case, an internal variable named LIMx will
be activated when the measurements will go outside the limits defined by the user through the dedicated setting menu.
– Furthermore, there are up to 4 counters (CNT1..CNT4) that can count pulses coming from an external source (through a digital input INPx) or the number of
times that a certain condition as been verified. For instance, defining a limit threshold LIMx as the count source, it will be possible to count how many times
one measurement has exceeded a certain limit.
– Finally it is possible to manage up to 8 analog inputs, connected to external analog sensors (temperature, pressure, flow etc). The value read from the
sensors can be scaled to any unit of measure, visualized on the display and transmitted on the communication bus. The value read from analog inputs is
shown on the dedicated display page. They can be used to drive LIMx limit thresholds.
– The following table groups all the I/O and the internal variables managed by the DMG800.
Cod. DESCRIPTION
INPx Digital inputs
OUTx Digital outputs
LIMx

Limit thresholds

BOOx

Boolean logic

REMx Remote-controlled variables
L x larms
PULx Energy count pulses
CNTx Counters
INx nalog inputs
OUx nalog outputs
– The status of each I/O or internal variable can be shown on the display in the dedicated page.
LIMIT THRESHOLDS (LIM)
– The LIMn thresholds are internal variables whose status depends on the out-of-limits of one particular measurement set by the user (e.g. total active power
higher than 25kW) among all those measured.
– To make the setting of the thresholds easier, since the limits can span in a very wide range, each of them can be set using a base number and a multiplier
(for example: 25 x 1k = 25000).
– For each LIM, there are two thresholds (upper and lower). The upper threshold must always be set to a value higher than the lower threshold.
– The meaning of the thresholds depends on the following functions:
Min function: the lower threshold defines the trip point, while the upper threshold is for the resetting. The LIM trips when the selected measurement is less
than the Lower threshold for the programmed delay. When the measured value becomes higher than the upper setpoint, after the delay, the LIM status is
reset.
Max function: the upper threshold defines the trip point, while the lower threshold is for the resetting. The LIM trips when the selected measurement is more
than upper threshold for the programmed delay. When the measured value decreases below the lower setpoint, after the delay, the LIM status is reset.
Max+Min function: both thresholds are for tripping. When the measured value is less than lower or more than upper setpoints, then, after the respective
delays, the LIM will trip. When the measured value returns within the limits, the LIM status will be immediately reset.
– Trip denotes either activation or de-activation of the LIM variable, depending on 'Normal status' setting.
– If the LIMn latch is enabled, the reset can be done only manually using the dedicated command in the commands menu.
– See setup menu M08.
1 -Status of the limit variable
2 - Value of measurement
3 - Function
4 - Type of measurement
5 - Upper threshold
6 - Threshold delay
7 - Lower threshold
BOOLE N LOGIC (BOO)
– It is possible to create max. 8 internal variables named BOO1..8, whose status depends on the Boolean logic combination of limit thresholds, inputs, outputs,
etc.
– The operands (INP, LIM etc) can be combined between each other with the following Boolean operators: ND, OR, EXOR, ND NOT, OR NOT, EXOR NOT.
– Every Boolean variable is the result of max 4 operands combined with 3 logic operations.
– Example: if one wants the Boolean variable BOO1 to be activated when the limits LIM1, LIM2 and LIM3 are all active or when the input INP1 is active, BOO1
must programmed as the combination of LIM2 ND LIM3 ND LIM4 OR INP1.
– It is not necessary to use all 4 operands for one Boolean variable. If for instance, one wants BOO2 to be active when INP1 or INP2 are active, then it is
possible to program BOO2 settings with the combination INP1 OR INP2, leaving the following logic operations set to --- (no operation).
– The BOOLE N LOGIC page displays, for every variable BOO1..8, the status of the single operands that are involved in the logic operation and the final result,
that is the status of the selected Boolean variable.
1 - Operand 1
2 - Logic operation 1
3 - Operand 2
4 - Operand status 1
5 - Status of the resulting variable
G
B
Range (x)
1...8
1...8
1...8
1...8
1...8
1...8
1...5
1...4
1...8
1...8