F-900 Instruction Manual 8/14/2017
1554 NE 3
rd
Ave, Camas, WA 98607, USA Phone: (360) 833-8835
47
www.felixinstruments.com
Figure 23: The removable piece of the F-900 terminal block.
Table 3: Designations of the 10 pins of the terminal block (On = 5V; Off = OV):
PIN
Function
1
Ground
2
Current Loop (reserved)
3
Plus 5 volts (limited through 4.7 ohm resistor)
4
Gas valve control (C
2
H
4
): when CONTL_OUT is ENABLE, OFF if C
2
H
4
> GAS_HI,
ON if C
2
H
4
< GAS_LO
5
Ready signal (5V): ON if during measurement (except correcting offset), OFF
otherwise
6
Alarm or error indicator: ON if one of the following happen: battery low/flow
blocked/signal out of range/sensor error, OFF otherwise
7
CO
2
analog output: 4-20mA for 0 - max CO
2
range (2000ppm or 100%)
8
C
2
H
4
analog output: 4-20mA for 0 - max C
2
H
4
range (20ppm or 200ppm)
9
Analog Input (reserved)
10
Analog control input for cleaning: use with CONTL_IN enabled
The digital outputs (4, 5, and 6) can sink up to 45mA to drive an optocoupler. They can only
source 0.1mA. Connect the optocoupler photoemitter anode to pin 3 (+5V) and the cathode to
the digital output
.
Setup Board
The Setup Board Menu should only be changed by a Felix Instruments technician. This menu
allows the user the select the type of hardware platform that the unit operates on, and should
only be changed at installation, or if hardware is upgraded.
The time interval between cpu/microprocessor calculations reaching the digital to analog
converter (DAC) output to pins 7 and 8 on the terminal block is every 200 milliseconds. The
internal sensor communicates analog signal to the analog to digital converter (ADC), which then
supplies digital output to the microprocessor. The microprocessor then provides digital values
Summary of Contents for F-900
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