Rockwell Automation 1771-QRD PULS FLOWMTR - Manual (Page 43)

Specifications
Appendix B
B–2
Signal Characteristics, Turbine Flowmeter or Magnetic Pickup: 50 mV
to 142 VAC RMS
The signal should be approximately sinusoidal and must be AC. The signal
must be greater than 50 mV peak to peak, and must be smaller than 400 V
peak to peak.
Signal Characteristics, TTL: 1.3 V threshold
The signal should be DC pulses with width greater than 20 uS. The logic
“1” level must be greater than + 1.3 V and smaller than +200 V while the
logic “0” level must be larger than –.7V and smaller than +1.3V.
The TTL mode is compatible with TTL, 4,000 series CMOS, and most
0–24 V systems. The TTL mode is not compatible with any signal format
with DC pulses riding on a fixed DC level greater than + 1.3 V.
Note: Signal type is selectable by swing arm jumper. Channel thresholds
are jumpered in pairs.
Input Impedance: 5 kOhm
" 30% resistive, minimum
Isolation: 1000 V minimum between channels and microcontroller, and
between channel pairs
Accuracy: 0.1%
"1 Hz for frequency t 3.0 kHz 0.2% "1 Hz for
frequency
u 3.0 kHz
Overrange Indication: Individual bit for each channel set to indicate rate
above 10 kHz
Overflow Indication: Individual bit for each channel set to indicate total
above 32, 767
Overrange Response: When a channel signal exceeds 10 kHz the rate
overrange bit will be set, the total reset to zero, and the rate for that
channel reported as zero
Maximum Operating Frequency: 10.0 kHz for PLC–3 and PLC–5, 0.999
kHz for PLC–2 (New Use)
Total Control: Overflow bit and total can be cleared by ladder logic.
Clearing total also clears overflow bit
Operational Limits