18
Rev. 1.0
11/08/2017
STF-R/C Hardware Manual
 400-820-9661
3.1.2  X5, X6, X7, X8 digital input signal
X5,X6,X7,X8: optically isolated, single-ended, 5-24VDC, minimum pulse width 100μs, maximum pulse 
frequency 5KHz
X5 can be used as enable input or general purpose input.
X6 can be used as alarm reset input or general purpose input.
X7 can be used as general purpose input. 
X8 can be used as general purpose input.
Because the input is an optically isolated circuit, a 5-24V power supply is needed. For example, 
you can use the power supply of the PLC when you are using a PLC control system, but if you 
want to connect a relay or mechanical switch to the input , you must need a power supply.
XCOM is an electronics term for a single-ended signal connection to a common voltage. In the 
case of STF series, if you are using a sourcing (PNP) input signals, you need to connect XCOM 
to the ground (power supply -), if you are using a sinking(NPN) input signals ,the XCOM need to 
connect to the power supply +.
Please use STF Congurator software for X5,X6,X7 and X8 function conguration. Following 
graphs shows some common connection methods for the inputs:
5-24VDC 
Power 
Supply
Connecting the inputs to a Switch or Relay
XCOM
X5/X6/X7/X8
+
-
STF
Drive
Switch or Relay
(closed = logic Low)
5-24VDC 
Power 
Supply
XCOM+
-
+
-
X5/X6/X7/X8
Connecting the inputs to a NPN type output
STF
Drive
NPN
Output
output
+
-
+
-
X5/X6/X7/X8
XCOM
Connecting the inputs to a PNP type output
5-24VDC 
Power 
Supply
STF
Drive
PNP
Output
output