Leds Of The I/O Modules; Terminal Layout - Mitsubishi Electric MELSEC ST Series Installation Manual

3.4.2

LEDs of the I/O Modules

LED
RUN
ERR.
3.4.3

Terminal Layout

The following illustrations show the signals that are assigned to the base module terminals,
when the corresponding electronics modules is mounted.
In the base module designations, the place holder " " stands for the letters "S" (spring clamp
terminal) or "E" (screw clamp terminal).
With the input modules the terminals supply the 24 V DC power for the connected switches or
sensors. Terminals with the same designations (for example "COM") are connected together
internally.
Digital Input Modules ST1X2-DE1 and ST1X4-DE1
MELSEC ST Series
LED Meaning
ON Normally operating
Flickering in 0.25 s intervals
Selected as a module to be replaced online.
Flickering in 1 s intervals
Flickering
b
Communication with the master station has stopped.
b
Slave parameter setting error
b
Other slice module fault
b
Internal bus error
b
The external power is off.
b
Hardware fault
OFF
b
Internal bus error
Hardware fault
ON
For output modules ST1Y2-TE2 and ST1Y16-TE2 only: The fuse has blown.
For output modules ST1Y2-TPE3 und ST1Y16-TPE3 only:
Flickering
Thermal protection or short circuit protection is activated
OFF Normally operating
ST1X2-DE1
Input X0 Input X1
11 21
–24 V DC –24 V DC
12 22
+24 V DC +24 V DC
13 23
Shield Shield
14 24
Base module ST1B- 4X2
Description of the Modules
ST1X4-DE1
Input X0 Input X1
11 21
–24 V DC –24 V DC
12 22
+24 V DC +24 V DC
13 23
Input X2 Input X3
14 24
–24 V DC –24 V DC
15 25
+24 V DC +24 V DC
16 26
Base module ST1B- 6X4
27