... Applicable to equipment for control of frequency,tacho,line-speed,level,etc;The instrument has several parameters setting function,easy to ... ,duty cycle,etc,please indicate when ordering.3, 4/5/6 digit display,with demical point switched automatically;Opical isolation for input ... analogue output 4-20mA or 0-10mA with range settable.5, RS232 or RS485 Modbus RTU protocol,connectable with various equipment ...