Power supply of the plc, X24 = power supply 24 v for plc, 5 power supply of the plc – HEIDENHAIN TNC 306 Service Manual User Manual
Page 40: 1 voltage measuring points on the plc board
SERVICE MANUAL TNC 306/360
Page 36
HEIDENHAIN Service
8.5 Power Supply of the PLC
The power supply line for the internal PLC is connected to the terminal block X24 (1 = +24V_A can be
switched off, 2 = +24V cannot be switched off, 3 = 0V).
The PLC supply voltages are protected with low-voltage fuses on the PLC graphics board.
+24V_A can be switched off
low-voltage fuse F 2.5A
+24V cannot be switched off
low-voltage fuse F 1.0A
The power supply line for the PLC I/O board PL 400 is connected to the terminal blocks X12 (0V) X13 (+24V_A
can be switched off) and the terminal strip X3/pin 12 (+ 24V cannot be switched off), (see PLC connection
diagram, section 8.5.2).
There is no fuse on the PLC I/O board (electronic power limiter).
8.5.1 Voltage Measuring Points on the PLC Board
Designation
Voltage Values
+ 5 V
+(5.05
±
0.05) V
+ 5 V* 1
+(5
±
0.25) V
+ 5 V* 21)
+(5
±
0.25) V
+ 24V
+(24
±
1.2) V
+ 24 V_A
+(24
±
1.2) V
1) potential-free