One or both these outputs can be provided. Generally the output is available at 9600 baud rate. Can be offered at other baud rates too. The data is in ASCII format with ‘,’ separator. Generally the output is continuous but can also be given at specified intervals or on demand. The serial output will be in a pre defined format and can include any headers, the present reading, peak or valley etc. These serial outputs allow the user to communicate with computers, PLCs or printers
Relay option with single, dual or up to 8 relays can be provided. Each relay set point (with sign), hysterisis (or dead band) and polarity (ie. to operate the relay above the setpoint or below the set point) are individually programmable over the entire span.
Generally the relays operate on the process values but can also be made to operate on the peak values or on other conditions. They can also be made to latch under specified conditions and then reset manually by the operator.
Generally the process controllers are mains operated. They can also be provided with other powering options like DC 6V, 12V or 24V. If battery operation is required, they can also be provided with charging options.
Additional displays can be provided to display the process value or the peak or the set point etc. These can be of any size from 0.3” to 6” or bigger. Generally these are powered from a separate mains supply and communicate with the master through serial interface. (RS232 or RS485)
The unit is generally calibrated in one of the basic units like kg. etc. Conversions to other units like lb. etc can be provided on request. Pressing of a key will convert the display reading to another unit. Also LEDs will be provided to indicate conversion that is currently active.
Some times the sensor output being measured may required to be adjusted to show the correct value of the physical parameter being measured like determining volume of non-linear tanks based on pressure or liquid level measured by an ultrasonic level sensor, a resistive sensor, or a float or linearizing non-linear transducers, such as thermistors. A look up table can be created for such applications and embedded into the unit. The unit can be made to fetch from this look up table and display.
The unit can be calibrated for sensors of different capacity like 10KG, 100KG, 1000KG etc. When a sensor of particular capacity is connected, the corresponding calibration can be recalled either by means of external switches or by selecting in the menu. One can have up to 8 such channels.
In the standard units the sampling rates of up to 100 samples/sec is achievable. Units with higher sampling rates can be provided on request. Such indicators can support up to 3000 samples/sec.
Isolated analog outputs like +/- 10V, +/- 5 V, 0-10V, 0 to 5V or 4-20 mA. can be provided for transmission to other instruments or the central control room. The output is linearized and scaled to the meter reading.
Red or Green display bar graphs (up to 50 segments) can be provided to display the process signals. They communicate with the master unit through serial interface. Provision is made in the master unit to scale the bar graph to fit the required range.
The test data can be stored in internal non-volatile memory and can be recalled latter or sent to the computer over serial link. The test data can be made to get stored automatically under specified conditions or can be stored on demand by pressing a key. Options are also provided to store the present value and / or the peak value, time etc.
Two or more instruments (like load indicator and displacement indicator) can be linked together through serial interface and made to capture one of the process value when the other reaches a specified condition ( ie. when load reaches a specified value say 5KG., the corresponding displacement can be captured or vice versa). The captured value is held in memory and can be recalled latter by the operator. Four such different capture points can be specified.
Generally, a 5V supply is provided in the unit for powering the sensor etc. If need be, other supplies like 24V etc. can also be provided.
An RTC module can be embedded inside the unit to provide the real time clock. This module will have its own battery backup and can maintain the time even when the power is switched off. This real time clock can be utilized for data logging or printing etc. The RTC will have both date and time functions.
Arithmatic computations like Mean, Max., Min., Std. Deviation, Square Root etc. can be performed on the process value and displayed. They can also be stored, recalled and printed in specified format.