Output Introduction Of Ultrasonic Flow Meters
As development of technology,ultrasonic flow meters have been developed better and better and widely used in many industries.Ultrasonic flow meters can be used for liquid and gas.In order to meet various requirement from different application,ultrasonic flow meters have been equipped with many outputs. The following is the main outputs of ultrasonic flow meters as below:
1.Analog output: Analog output is mainly 4-20mA current loop output. The current loop outout has two ways: one is self-powered way, which doesn’t need external power to the loop;the other is loop-powered way,which need external to the current loop.Our ultrasonic flow meter can suppor 0-20mA current output and the curent output mode can be set as request.
2.OCT(Open Collect Transistor Output) pulse output. The output is widely used and in our ultrasonic flow meters,the output can be set,including pulse width,output items,etc. The OCT output has istolate way and un-isolated way.
3.Relay output. Relay output is used to control switch ON/OFF. For example, to control the pump.
4.RS232 port. RS232 port is widely for instruments,also including ultrasonic flow meters. The port is usally 9-pin or 9-hole.By RS232 port,ultrasonic flow meters can be connected to computer,and data can be stored to PC. It usually need to set serial communication port in order to successful communication.
5.RS485 port. RS232 port has a very short communication distance,about several meters, and it can’t meet the long distance communication. Thus RS485 will be a better choice as it can support tens to thousand meters distance communication. By RS485,some communication protocol can be used, for example, MODBUS protocol,M-BUS protocol.
6.USB way: as computer technology development, USB port is widely used and has been standard configuration.If instrument has no USB port, it can be use Rs232-USB converter.
7.Wireless way: the output way include GPRS/GSM way, Radio way,infrared port way,etc.
When use different output, users should know different communication protocol which mainly includes 3 kinds:
1). MODBUS protocol: MODBUS including two ways: MODBUS-RTU and MODBUS-ASCII. MODBUS usually use RS485 port as its output channel. MODBUS can be used for network.
2.Hart Protocol: Hart protocol is widely used in flow and pressure. Hart protocol usually use 4-20mA output as its output channel. HART is master-slave way and not suitable for network. If want to combine network, user can buy our HART-MODBUS converter which has been widely used for pressure transmitters and flowmeters.
3.Meter-BUS protocol: The protocol is mainly used in EU and for water meter and heat meter and gas meter,etc. It usually use RS485 port as its output channel.