3.4.2
LEDs of the I/O Modules
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 "
첸
" 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
Description of the Modules
MELSEC ST Series
27
LED
LED
Meaning
RUN
ON
Normally operating
Flickering
Flickering in 0.25 s intervals
Selected as a module to be replaced online.
Flickering in 1 s intervals
쎲
Communication with the master station has stopped.
쎲
Slave parameter setting error
쎲
Other slice module fault
쎲
Internal bus error
OFF
쎲
The external power is off.
쎲
Hardware fault
쎲
Internal bus error
ERR.
ON
Hardware fault
For output modules ST1Y2-TE2 and ST1Y16-TE2 only: The fuse has blown.
Flickering
For output modules ST1Y2-TPE3 und ST1Y16-TPE3 only:
Thermal protection or short circuit protection is activated
OFF
Normally operating
+24 V DC
–24 V DC
Input X1
+24 V DC
–24 V DC
Input X0
Base module ST1B-
첸
6X4
+24 V DC
–24 V DC
Input X2
+24 V DC
–24 V DC
Input X3
11
12
13
14
15
16
21
22
23
24
25
26
11
12
13
14
21
22
23
24
Shield
+24 V DC
–24 V DC
Input X1
Shield
+24 V DC
–24 V DC
Input X0
Base module ST1B-
첸
4X2
ST1X2-DE1
ST1X4-DE1