Dynasonics TFX Ultra Transit Time Flow Meters - Manual (Page 30)

ALARM OUTPUTS
The flow rate output permits output changeover at two separate flow rates allowing operation with an adjustable switch
deadband. Figure 27 illustrates how the setting of the two set points influences rate alarm operation.
A single-point flow rate alarm would place the ON setting slightly higher than the OFF setting allowing a switch deadband to
be established. If a deadband is not established, switch chatter (rapid switching) may result if the flow rate is very close to the
switch point.
Minimum
Flow
Maximum
Flow
Output ON Set OFF Set ON
Deadband
Output OFF
Figure 27: Single point alarm operation
OTE:
N
All control outputs are disabled when USB cable is connected.
Batch/Totalizer Output for Flow Only Version
Totalizer mode configures the output to send a 100 mSec pulse each time the display totalizer increments divided by the TOT
MULT. The TOT MULT value must be a whole, positive, numerical value. This output is limited to 1 Hz maximum.
For example, if the totalizer exponent TOTL E is set to E0 ×1 and the totalizer multiplier TOT MULT is set to 1, then the output
will pulse each time the totalizer increments one count, or each single, whole measurement unit totalized.
If the totalizer exponent TOTL E is set to E2 ×100 and the totalizer multiplier TOT MULT is set to 1, then the control output will
pulse each time the display totalizer increments or once per 100 measurement units totalized.
If the totalizer exponent TOTL E is set to E0 ×1 and the totalizer multiplier TOT MULT is set to 2, the control output will pulse
once for every two counts that the totalizer increments.
Totalizer Output Option for Energy Meter
Energy units can be ordered with a totalizer pulse output option. This option is installed in the position where the Ethernet
option would normally be installed.
Optional Totalizing Pulse Specifications
Optional Energy Usage Totalizing Pulse Output
Signal One pulse for each increment of the totalizers least significant digit.
Type Opto-isolated, open collector transistor
Pulse Width 30 mSec, maximum pulse rate 16 Hz.
Voltage 28V DC maximum.
Current 100 mA maximum (current sink).
Pullup Resistor 2.8 …10 k Ohms
OTE:
N The totalizer pulse output option and the Ethernet communications output can not be installed in the same energy
unit at the same time.
ALARM OUTPUTS
Page 30 March 2014