Technical data
10.4 Outputs
SITRANS F Ultrasonic flowmeters FST030 (Modbus)
118
Operating Instructions, 08/2017, A5E37367739-AC
Description
Channel 1
Cable
Standard industrial signal cable with up to 3 twisted pairs with overall screen can be con-
nected between the transmitter and the control system. Individual pair or overall screen is
optional depending on user requirements.
Voltage range
Max. 24 V DC (active)
14 to 30 V DC (passive)
Table 10- 7 Current output (Channels 2 to 4)
Description
Channels 2 to 4
Signal range
0/4 to 20 mA
Resolution
0.4
μA
Load
•
Ex i: <470 Ω
•
Non-
Ex: <770 Ω
Time constant (adjustable)
0.0 to 100 s
Fault current
Measurement range (mA)
Lower fault current (mA)
Upper fault current (mA)
4-20 NAMUR
3.8 - 20.5
3.5
22.6
4-20 US
4.0 - 20.8
3.75
22.6
4-20 NAMUR
4.0 - 20.5
2.0
22.0
4-20 US
4.0 - 24.0
2.0
25.0
0-20 NAMUR
0.0 - 20.5
0.0
22.0
0-20 US
0.0 - 24.0
0.0
25.0
Customized fail-safe mode
•
Last valid value
–
Lower fault current
–
Upper fault current
•
Fail-safe value
•
Current value
Galvanic isolation
All inputs and outputs are galvanically isolated PELV circuits with 60 V DC isolation from
each other and ground.
Maximum test voltage: 500 V AC
Cable
Standard industrial signal cable with up to 3 twisted pairs with overall screen can be con-
nected between the transmitter and the control system. Individual pair or overall screen is
optional depending on user requirements.
Voltage range
Max. 24 V DC (active)
14 to 30 V DC (passive)
Table 10- 8 Digital output
Description
Channels 2 to 4
Pulse
41.6 µs to 5 s pulse duration
Resolution
1
μs
Frequency
0 to 10 kHz, 50 % duty cycle, 120 % overscale provision
Resolution
0.2 Hz
Load
< 750 Ω
Time constant (adjustable)
0 to 100 s
Active
0 to 24 V DC, 87 mA, short-circuit-protected