TRANSPAKTM T773
Frequency Input, Isolating Field Configurable Two-Wire Transmitter
Provides an Isolated Current Loop in Proportion to a Frequency Input
Description
Benefits
Eliminates Ground Loops Digitally-Synthesized, Field Configurable Ranges (105Hz to 18kHz) Wide Ranging Zero and Span Adjustability Direct Magnetic Pickup Input Velocity/Flow Applications Protects Equipment with 1000VRMS Isolation
The T773 isolating two-wire transmitter has 5 input ranges and 2 output ranges, all of which are field selectable via top-accessed DIP switches. The T773 can accept square, triangle or pulse waveforms up to 18KHz with amplitudes from 10mVrms to 35V peak-to-peak. The T773 provides 1000Vrms of transformer-coupled isolation with outputs of either 4-20mA or 10-50mA. Current outputs are in proportion to a selected frequency input. The T773 has 30% zero “turn-up” and 80% span “turn-down” adjustments within any user-selected input range. For example, Range 3 of Table 1 specifies 0 to 2100Hz with a minimum span of 420Hz (2100Hz - 420Hz = 1680Hz, or 80%). This 80% adjustability allows the user to field calibrate the unit for the maximum range of 0 to 2100Hz down to the minimum range of 0 to 420Hz. The maximum obtainable offset is 30% of the calibrated span: a calibrated range of 0 of 1000 Hz can be offset by 300Hz (e.g., 300Hz to 1000Hz).
Application
The T773 is useful in any application requiring isolation of a 2-wire loop current from a pulse output transducer, such as a magnetic pickup or a turbine flowmeter. The output of the T773 can be used to drive a digital meter for direct display of flow or velocity, or to interface with a computer or PLC for monitoring and control applications. The T773 is CSA approved for intrinsically safe operation in Class I, Division 1, Groups A, B, C and D hazardous locations when installed per manufacturing drawing number.
Options
U Urethane Coating of internal circuitry for protection from corrosive atmospheres.
Calibration
Factory settings are: Input Range: 1 Output Range: 4-20mA 1. Open the access lid on the top of the unit (see Top View Diagram). 2. Select the output range using switch S6. The CLOSED position selects a 10-50mA output. The OPEN position selects a 4-20mA output. 3. Select the input range from Table 1 and configure switches S1 through S5. 4. Determine the percent of span by the ratio of the desired maximum input to the input limit in Table 1 (e.g., 1000Hz/2100Hz = 48%). 5. Set the step Span rotary switch to the desired percent of span (e.g., 48% = position 4).
Percent of Span 100% ≥90% ≥80% ≥70% ≥60% ≥50% ≥40% ≥30% ≥20% Position A 9 8 7 6 5 4 3 2
9. Set the calibrator to the desired minimum and adjust the fine zero to obtain an output of either 4mA or 10mA. 10. Set the calibrator to the desired maximum and adjust the fine span to obtain an output of either 20mA or 50mA. Repeat steps 9 and 10, if necessary, for maximum accuracy. Note: If loop current "swings" on input ranges 1-2, close S-5 for extra filtering.
Table 1: T773 Input Ranges
Range 1 2 3 4 Key: Switch Position Input Limits 0 to 18KHz 0 to 9KHz 0 to 2100Hz 0 to 525Hz = 1 = ON or Closed Minimum Span 3600Hz 1800Hz 420Hz 105Hz 1 2 3 4 5
Field Mounting
The T773 is designed for installation in industrial field environments. A sealed, diecast aluminum housing protects against corrosion, moisture, dust and electrical noise such as radio-frequency (RFI) and electromagnetic (EMI) interference. For protection against extreme moisture, hosedirected water (NEMA 4) or hazardous environments, use the T805 explosion-proof housing. The T805 provides a 1/2" and 3/4" FPT port for operation in harsh process environments. The T805 is FM and CSA certified for use in Class I, Groups B, C & D and Class II, Groups E, F & G hazardous locations.
T805 Explosion Proof Housing (Optional)
6. Determine Zero turn-up % by the ratio of desired minimum input to the desired maximum input (e.g., 0/1000Hz = 0%). 7. Set step Zero turn-up switch to offset %. (e.g., 0% = position 0).
Zero Turn-Up % 0% ≤10% ≤20% ≤30% Position 0 1 2 3
8. Connect the input to a calibrated frequency source. Connect the output loop to a voltage supply and monitor the output current (refer to the terminal wiring).
Top View Diagram
Mounting Hardware
T805 Field Mountable Housing (EP, NEMA 4 rated) 3/4" Hub (Includes T903 Retainer Ring & NEMA 4 Gasket)
T773 Terminal Connections
1. 2. 3. 4. 5. 6. Loop Output (-) Loop Output (+) No Connection Input Frequency Input Frequency Shield (Case)
Note 1: For best RF & common mode rejection, ground the case (pin 6). Note 2: RL represents any other device loads in the current loop.
Specifications
Input Span Range (Max/Min) See Table 1 Type: Capacitive coupled Minimum Amplitude: 105-2150Hz: 10mVrms >2150Hz: 15mVrms Maximum Amplitude: 35Vp-p Impedance 100-1KHz: >6k Ohms >1KHz: >40k Ohms Output Span 4-20mA/10-50mA, switch selectable Minimum Output Current 3.3mA, typical Maximum Output Current 4-20mA: 24mA, typical 10-50mA: 58mA, typical Supply Voltage Range 4-20mA: 13 to 75VDC 10-50mA: 13 to 50VDC Line Regulation 0.07% of span (13-75V) Load Regulation 0.05% of span (0-3k Ohms) Voltage Drop 13VDC @ 20mA
Stability Zero:
±0.015% of span/°C, typical, ±0.028%/°C, max. Span: ±0.022% of span/°C, typical, ±0.043%/°C, max. Overall Accuracy (Includes Linearity, Hysteresis, Stability) ±0.2% of adjusted span, max. Zero Adjustability 30% “turn-up” of span Span Adjustability 80% “turn-down" of full-scale limit (Table 1) Repeatability ±0.05% of span Response Time (63% response) 9KHz: 40mSec. Output Ripple, P-P (% at max. input range frequency; 0% turn-down) Range 1: 0.5% (18KHz) Range 2: 0.5% (9KHz) Range 3: 0.7% (2100Hz) Range 4: 1.2% (525Hz)
Common Mode Rejection 60Hz: 97dB, DC: 120dB Common Mode Range 60Hz: 75Vrms, max. DC: 1KV, max. RFI Effect (1.5W, 470MHz at 1.5 ft.)
