TEL1-PCM

Version 1.4
TEL1-PCM
Digital Telemetry System for Strain Gage
Applications on Rotating Shafts
“Remote Gain and Auto Zero Settings”
• Easy Installation and Operation • Inductive Digital Transmission
• Strain Gage Sensors (>350 Ohm) • Range up to 20mm (40mm Option)
• Full and Half-bridge Configuration • High Noise Immunity
• Sensor Excitation 4 Volt DC • Multi-System Operation Available
• Remote Auto Zero Adjustment • Signal Bandwidth dc to 1200Hz (-3dB)
• Remote Gain Setting: 250 - 8000 • Outputs ±10V and Digital Interface (Option)
• External Shunt Calibration • System Accuracy

Version 1.4
General Description
The TEL1-PCM single-channel telemetry system offers a simple solution for the wireless transmission of strain gage signals
from rotating shafts, enabling torque, strain, force, acceleration and pressure measurements to all be made. The very small
encoder 35 x 18 x 12 mm weighs only 13g. The transmitter (encoder) assembly is simply mounted on the rotating shaft with a
special fiber reinforced tape.
Power to the shaft transmitter and the digital data transfer between transmitter and receiver is realized inductively, for
continuous, maintenance-free operation.
Functional Description
The TEL1-PCM transmitter provides a pulse code modulated signal (PCM) to an induction winding around the shaft. The
magnetic field of this winding transfers the signal to the pickup coil. From there the signal is transferred by cable (5 m) to the
receiver. The maximum distance between the transmitter coil and the pickup is 20mm (with standard head).
The receiver unit offers a BNC connector at the front panel with an analog output of ±10 V and an optional digital output for
direct data transfer using a PCM interface ECIA100 (for notebooks) or IF16 (PCI Desktop). An LED bar indicator shows the
signal level and successful Auto Zero calibration. Positive or negative signal overload is indicated by the last LED´s on the bar
graph. These OVL-LED´s operate in peak-hold mode and are reset by pressing the overload switch.
Strain gage sensors (>350 Ohm) in full or half-bridge configuration can be directly connected to the transmitter. The excitation
is fixed to 4 Volt DC and a switch on the receiver side remotely sets the gain. An Auto Zero (AZ) adjustment is executed by
pressing the AZ button on the front panel of the receiver. A yellow LED in the middle of the LED bar indicator indicates a
successful balance operation. The yellow LED flashes while the balance is in progress. When completed the LED continuously
illuminates. The setting is stored in non-volatile FlashRAM and thus is not lost during power-off.
Additionally sensor calibration can be made using an external resistive shunt (+ or -).
TEL1-PCM Set Contains:
2

Version 1.4
Technical Data
TEL1-PCM-STG
Strain gage: Full and half-bridge >350 Ohm,
Excitation: 4 Vdc (fixed)
Gain: 250, 500, 1000, 2000, 4000, 8000 (selectable from receiver side)
3
Gain
Resolution
Auto Zero range
250
12 bit
100%
500
12 bit
200%
1000
12 bit
400%
2000
12 bit
400%
4000
12 bit
400%
8000
11 bit
400%
Shunt Cal: Via external resistor for positive and negative calibration
AZ: Auto Zero balance (selectable from receiver side)
Analog signal bandwidth: 0 - 1200 Hz (-3 dB)
Operating temperature: -10 to +80 °C (14 to 176 °F)
Sampling rate: 7.5 kHz
Dimensions, without connectors: 35 x 18 x 12mm (1.4 x 0.7 x 0.5 in)
Weight: 13 gm (0.4 oz)
Static acceleration: up to 1000g
Powering: Inductive (optional Battery, see TEL1-PCM-BATT)
Housing: splash-water resistant IP65 (except the connector pins)

Front Rear
Technical Data
TEL1-PCM-DEC
Analogue output: ±10V via BNC connector
Digital output for PCM Interface IF16 (ECIA100): OPTION
Gain setting : Remotely via front panel switch 250 to 8000
Auto Zero setting: Remotely via micro switch (press 1 second)
Overload LED’s (Red ON): Reset via micro switch
Auto Zero LED (Yellow): ON balance completed
OFF no balance
Flashing, balance in progress
Signal Level LED's (Green): Bargraph +/-
Error LED (Red ON): Data transmission error
Distance LED (Red Flashing): Distance out of range
Power ON LED (Green): Power ON
Output to Powerhead: 5-pin Tuchel
Input Power: 10-30V dc, 7-pin Tuchel
Operating temperature: -10 to +70 °C (14 to 158 °F)
Dimensions, without connectors: 200 x 105 x 44 mm (7.9 x 4.2 x
1.75 in))
Weight: 950 gm (2.1 lb)
Static acceleration: Up to 200g
System accuracy (without sensor): ± 0.2 %
TEL1-PCM-Powerhead/Pickup (standard version)
Function: Inductive powering of the TEL1-PCM-STG unit and
receiving PCM magnetic field in PCM modulated code
Distance between the transmitter coil and the pickup is 20mm
Output to TEL1-PCM-Decoder: 5-pole Tuchel Plug incl. 5m cable
(max)
Operating temperature: -10 to +80 °C (14 to 176 °F)
Dimensions, without cable: 45 x 60 x 25mm (1.8 x 2.4 x 1 in)
Weight: 400 gm (14 oz), with 5m (16') cable
Housing: Splash-water resistant IP65 (except connector).
CAESAR Datensysteme GmbH CAESAR DataSystems Inc CAESAR DataSystems Ltd
Keltenring 16, Oberhaching 24350 Indoplex Circle 2 Faraday Court, Rankine Road
82041 Munchen
Version 1.4
Phone: +49 (89) 6130490
Fax: +49 (89) 61304997
Farmington Hills, MI, 48335
Phone: +1 (248) 888 46268
Fax: +1 (248) 888 8269
Daneshill, Basingstoke
Hampshire RG24 8PF
Tel: +44 1256 332147, Fax: 332274