OT. Schematic questions

Two questions.

1. For those of you that use the relay expansion boards such as:
https://www.automationdirect.com/ad...ions_Modules_(Complete_List)/ZL-RRL16HDF-24-1

How do you show on the schematics that the relays are all part of a device? Before I have just shown the relays as stand-alone coils with no real connection to them being part of a "board".



2. Next question is what do you typically use for a pressure, flow, temperature transmitter symbol? My symbols are just basically square boxes with some wire connections. Does anyone have a nicer representation of for instance MA output pressure transmitter?

put the device on a separate page, or put a box around each coil, the contacts can be on other page with references.

2. that is depending on your cad software.
have a look at www.qelectrotech.org for a free ECAD program. with lots of symbols.

In general, to show a mechanical connection among devices, I will use a dashed line or enclosing rectangle (with dashed linetype).

So if your relay coils are all on a sheet, put a big dashed rectangle around them. Sometimes it is useful to put the part number or a brief description at the edge of this rectangle or if it is extended across multiple sheets, a note explaining that.

I use JIC symbols and make my drawings old school 'merican style, and I have not found a good symbol I like for transmitters. So, I make a rectangle with attributes for terminal points and put a multi-line text object in the middle of it with a description.

OkiePC said:

In general, to show a mechanical connection among devices, I will use a dashed line or enclosing rectangle (with dashed linetype).

So if your relay coils are all on a sheet, put a big dashed rectangle around them. Sometimes it is useful to put the part number or a brief description at the edge of this rectangle or if it is extended across multiple sheets, a note explaining that.

I use JIC symbols and make my drawings old school 'merican style, and I have not found a good symbol I like for transmitters. So, I make a rectangle with attributes for terminal points and put a multi-line text object in the middle of it with a description.

Click to expand...

+1, I do the same exact thing.

OkiePC said:

In general, to show a mechanical connection among devices, I will use a dashed line or enclosing rectangle (with dashed linetype).

So if your relay coils are all on a sheet, put a big dashed rectangle around them. Sometimes it is useful to put the part number or a brief description at the edge of this rectangle or if it is extended across multiple sheets, a note explaining that.

I use JIC symbols and make my drawings old school 'merican style, and I have not found a good symbol I like for transmitters. So, I make a rectangle with attributes for terminal points and put a multi-line text object in the middle of it with a description.

Click to expand...

+1 From the maintenance side.
If I see something wrapped in dashed lines I expect that is either in a separate cabinet or a separate component. As long as there is some explanation, I'll find it.


Wubba.

Thanks for the input guys. I will do that for the relay cards. I've done something similar in the past for for sensor input "modules".

Now to find a better transmitter symbol than my box. I know I've seen something before with a diagonal line seperating the pressure to ma side. Similar to what I use for an ac to dc power supply.

What I do for a transducer is use a standard sensor/switch wired to want I use for a servo or analog output.
This is an example of a pressure transducer:

We use EPLAN.

1: If a device has a mounted option, I would use the tag of the device, with perhaps a subordinate tag. So say PLC device A151 has a relay option installed, I would maybe call that -A151-K1.

2: See picture.

Schematics aren't the same as wiring diagrams. Schematics are intended to show the function of a circuit, for use in design and troubleshooting. Wring diagrams show point to point connections or construction.

I never liked the convention of showing all the PLC I/O on a single block for schematics. The same would apply to a relay card. If the circuit is complex it is difficult to show the related components clearly. I also separate discrete circuits from analog circuits. With the proper label you can easily identify the PLC I/O card and channel that the I/O or relay is associated with.

I've attached samples. Over the years I've had many contractors tell me that my drawings were the easiest to work with they had used.