... :0.01Hz--100KHz(max 100KHz) Accuracy:0.01Hz. Digital 4/5/6 LED Frequency Meter (FA) Features:1, Input: various wave form ... ,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 ...