ABB SpiritIT Flow-X Instruction Manual page 24

2 4 S P I R I T
Pulse inputs
When connected to a device that resides in a hazardous
area, safety barriers or galvanic isolators may be
required to be interposed between the device and the Spirit
Flow-X flow computer. Refer to the device documentation for
adequate information.
Each digital channel can be configured as a pulse input.
Depending on the type of pulse signal a single- or dual pulse
input will be allowed for each flow module. Each flow module,
depending on the hardware version, supports one or multiple
pulse input.(single or dual).
To accommodate for different type of pre-amplifiers each pulse
input channel supports two threshold levels for signal activation.
For channels 1 through 8 the threshold level is selectable
between 1.25 V and 12 V and for channels 9 through 16 between
3.6V and 12 V. The default is 12 V for all 16 channels.
Both single and dual pulse inputs are supported. In dual pulse
mode, ISO 6651 pulse integrity checking at level B is always
enabled. Level A support (correction) may optionally also be
enabled.
It is common practice to use pre-amplifiers to condition signal
level from the meter pickup-coils. The following figures illustrate
typical wiring when using pre-amplifiers.
+V
(external)
Pull-up
resistor
Open
collector
output
0V
(external)
Figure 6-12 Pre-amplifier with open-collector output
+V
(external)
Voltage
output
0V
(external)
Figure 6-13 Pre-amplifier with voltage output
Time period inputs
When connected to a device that resides in a hazardous
area, safety barriers or galvanic isolators may be
required to be interposed between the device and the Spirit
Flow-X flow computer. Refer to the device documentation for
adequate information.
I T F L O W - X I N S T R U C T I O N M A N U A L | I M / F L O W X - E N
Digital
[1..16]
0V
Digital
[1..16]
0V
Each digital channel can be configured as a time period input,
typically used to connect densitometers (also called density
transducers or density meters) and specific gravity transducers.
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Each Flow-X/M module supports 4 time period inputs.
Time period inputs have to be connected to one of 16 digital
channels provided by each flow module. Make sure that the used
digital channel number has been set up properly in the Spirit
Flow-X configuration.
For Solartron densitometers a 1 micro-Farad capacitor is
required between the pull-up resistor and the digital channel as
shown in the following figure.
Sig +
Sig -
Solartron
Densitometer
Figure 6-14 Solartron densitometer connection (loop powered by
Flow-X)
Note : When the loop is externally powered a second 1 uF
capacitor needs to be installed between the Solartron 'SIG-' and
the Flow-X 'Common'. The capacitor should not have a polarity
(+/-), electrolytical capacitors should not be used.
Digital outputs
When connected to a device that resides in a hazardous
area, safety barriers or galvanic isolators may be
required to be interposed between the device and the Spirit
Flow-X flow computer. Refer to the device documentation for
adequate information.
Each digital channel can be configured to operate as a digital
output in which case it acts as an open collector. When the
digital output is activated, the digital signal is connected to the
flow computer common ground.
24V out
Digital
[1..16]
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Figure 6-15 Internally powered digital output
24V out
470 Ohm
1 uF
Digital
[1..16]
Common
Load
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Flow-X
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