In PLC's, the input and output modules are controlled by sip, dip switching. what scheme is used in this switching. As I am student,
therefore add some words about sip, dip switching.

 

These are usually set up to provide 1's or 0's to some type of port accessable to the processor or possibly fixed logic. Most often they provide a binary address or data byte that the initialization code uses in setup or directly as an address to access IO. The trend is to soft configuration where config words are held in non-volitile memory. However, sometimes option data is needed before the executive is in control of the machine and sometimes jumpers are used because they are absolutely non-volatile and flash or nvram could be corrupted. The hardware typically has a resistor or internal current source or sink that ensures the input is high or low with the switch open and closing the switch simply grounds or applies Vcc to the input to switch it to the other state. On inexpensive equipment or where it is expected that configuration will be infrequent, jumpers are used to save the cost, space and layout needs for a switch. Since all the switches typically either ground inputs or all switch to Vcc, a SIP with a common terminal can save board space.

Soft configuration is very convenient as long as everything is working. Hard configuration is much more obvious if it isn't. And, of course, with soft configuration, you need the proper software, working, to do anything. This has lead to interesting scenarios where improper soft configuration prevents you from fixing the improper configuration. Hence there's usually some sort of a jumper or switch or removing the battery to wipe everything and start over.

Switches and jumpers can be used of course, for other purposes for example, to change filtering, or power configuration, etc. These need to be considered on an individual basis as you seldom see a schematic, The point is, that it is not possible to assume that you can change them randomly without information.

That's board switches and jumpers in a nutshell.

Hope this helps.

Regards

cww

 

In PLC's, the input and output modules are controlled by sip, dip switching. what scheme is used in this switching. As I am student, therefore add some words about sip, dip switching

Not sure what you mean by sip switching. But if you are talking about a DIP switch, all it is is a bank of switches in a dip (dual-inline package) or in other words, like an ic chip (although they getting less common these days)

By switching these switches (usually two position) you can select options which are completely specific to the circuit/software you are using. There is no standard. You could be indicating baud rate, device address, input/output direction, clock speed, memory size, etc.

Typically you only switch these while the unit is powered off and it will read them in at "boot" time.

They are usually tied to ground on one side and a pullup resistor on the other side (also connected to some other computer input or gating chip).
(Multiplexing schemes can be done by supplying the common leg as a "bank select" but that's beyond the scope of the post.)

I haven't seen sip switches, but my experience is more limited than many.

Rufus