TRACKER 240 SERIES Load Cell and Weighing Indicators

Display The user can configure the Tracker 240 series for the required engineering units and display resolution. The resolution is user configurable for 1, 2, 5. and 10 digits. This can be useful if a steady reading is difficult to achieve. Normally the full resolution would be displayed. For noisy signals an independent display filter is provided. The user can select the display update rate to be 2, 4 or 10 per second, and the brightness can be adjusted to suit ambient lighting conditions. Calibration Scaling and User Linearisation Calibrating the Tracker 240 series to load cells can be achieved in one of two ways. Values from the strain gauge can be entered manually or the Tracker can read the actual output from the transducer at two points in the range, normally at zero and another point near the maximum load to be measured. These measured values are stored with their associated display values as the calibration parameters. For more demanding applications, up to 8 points can be independently calibrated to compensate for transducer non linearity. Analogue Output The user programmable analogue output allows the Tracker 240 series to transmit the measured display value or the Maximum, Minimum, Average, or a value sent via the serial interface. The analogue output can be scaled for any portion of the display range and is configurable for 4-20mA, 0-20mA or 0-10 Volt signals. Electrical isolation ensures that problems with earth loops are avoided. Serial Communications The Tracker 240 series are equipped with an isolated RS422/ 485 serial communications interface to allow connection to computers or PLCs. Three protocols are provided as standard to allow easy integration with most SCADA packages. The user can select  Master Mode to allow digital transmission to a remote  Repeater display or printer. RS232 can be supplied instead of RS422 / 485 - consult your supplier. Sensor Connections The Tracker 240 series use a 6-wire ratiometeric method of measurement. Up to four 300 ohm load cells can be connected in parallel. More can be used if the resistance is higher ( e.g. 8 x 600 ohm load cells) and the total current does not exceed 120mA at 10Vdc. An external 10Vdc supply can be used, if required, still retaining the ratiometric measurement capability. Normally the transducer connections would be wired as shown. Digital Status ( Logic) Inputs Two logic inputs are provided to allow remote control of the indicator functions via external devices such as switches or PLCs. The inputs may be activated by volt free contacts or open collector TTL outputs. The two inputs can be individually programmed by a user to perform one or more of the following functions: - Tare Zero Part Count Display Hold Display Maximum ( Peak) Display Minimum ( Valley) Display Average Display Reset ( Peak Picking Mode) Display Test ( Lights all Display Segments) Keyboard Lock Alarm ( Latch) Reset Alarm Disable Analogue Output Hold Reset Max, Min and Average Start Fill Front Panel Function Keys The five front panel buttons can be used to set