Siemens S5-135U/155U appendix Slide Switch S2

Digital Input/Output Modules

Changeover of the The operation of Channels 1.0 to 1.7 as inputs or outputs merely depends on

I/O bytethe user program. You define the byte as an input with a read access to the DI/DQ; you define the byte as an output with a write access. The double-function of the byte also allows the output byte to be read out.

Unused channels should not be wired nor addressed by program. When these channels are used as inputs, it should be noted that the corresponding bits in the output register remain at logic 0. This resetting of output registers is executed automatically after power-up of the PLC or EU.

Note

When at least one of Channels 1.0 to 1.7 is operated as an input, the connected sensors and the 1L+ terminal must have the same power supply. If this is not the case, the input voltage acts on the 1L+ terminal. The resultant supply to the output amplifiers of Channels 0.0 to 1.7 causes currents to be drawn via the wired input terminal; these currents may assume different values, depending on the control states of the outputs.

With the DI/DQ 482, you must set slide switch S2 to setting 1 for operation without the IP 257.

	Slide Switch S2
	Local Bus Interface
Figure 8-6	Slide Switch S2 on the DI/DQ 482

System Manual	8-13
C79000-G8576-C199-06