
Publication 1794-6.5.11 - November 1997
Appendix
A
Specifications
What This Appendix
Contains
This appendix contains the frequency accuracy and general specifications
of the Frequency Input module (cat. no. 1794-IJ2).
Specifications – 1794-IJ2 Frequency Input Module
Input Specifications
Number of Input Channels
2
Number of Inputs per Channel
2 – Frequency and Gate (gate used to establish direction)
Input Frequency (maximum)
1-32KHz w/Sine Wave; 1-32KHz w/Square Wave Input
Frequency Value (maximum)
32,767 or 3,276.7 (dependent on range)
Input Pulse Width (minimum)
20µs
Resolution/Accuracy
Refer to Resolution/Accuracy table on page 4
On-State Voltage
(Minimum)
10V (24V IEC
+
1 proximity, encoder input or switch inputs)
On-State Voltage
(Nominal)
(selected by terminal base
connections)
50mV ac, 28V ac peak – Extended Magnetic Pickup
500mV ac, 28V ac peak – Magnetic Pickup
≤
3V – Vortex Flowmeter low range
≥
6V – Vortex Flowmeter high range
24V dc IEC1+ Proximity or Encoder input
24V dc Contact Switch input
On-State Voltage
(Maximum)
Limited to isolated 24V dc power supply maximum
On-State Current
Minimum
Nominal
Maximum
2.0mA
9.0mA
10.0mA
Off-State Current
Minimum
1.5mA into 24V dc IEC1+ Terminal
Off-State Voltage
Maximum
5.0V dc on 24V dc IEC1+ Terminal
Wire-Off Detection
0.4mA for proximity, encoder, or contact switch with 50k
Ω
shunt resistor
Frequency Input Impedance
>
5K
Ω
for 50mV extended magnetic pickup
>
5K
Ω
for 500mV magnetic pickup
>
10K
Ω
for 3V vortex flowmeter
>
10K
Ω
for 6V vortex flowmeter
>
2.5K
Ω
for 24V dc IEC1+ proximity or encoder input
>
2.5K
Ω
for 24V dc contact switch input
Gate Input Impedance
>
5K
Ω
for 50mV extended magnetic pickup
>
5K
Ω
for 500mV magnetic pickup
>
2.5K
Ω
for 24V dc IEC1+ proximity or encoder input
>
2.5K
Ω
for 24V dc contact switch input
Output Specifications (meets IEC 1A 24V dc output specification)
Number of Outputs
2 isolated
Output Voltage Source
Customer supplied
Output Voltage
Minimum
Nominal
Maximum
10V dc
24V dc
31.2V dc
Off-State Voltage
Maximum
31.2V dc
Specifications continued on next page.