this is which protocol ??

hi
I have a device that has a communication port but I do not know which type of protocol.
I've measured the voltages on pins , that The following values were obtained :


in your opinion , this is which protocol ??
in The manufacturer's catalog Been picture following :


Also come in the catalog the following descriptions :

mohammad2060 said:

in your opinion , this is which protocol ??
in The manufacturer's catalog Been picture following

Click to expand...

Just a WAG

The manufacture manual has a type error and it should read RS422 not RS424

Looks like a RS232 to RS422 adapter, we sell them http://www.plccable.com/data-converters-rs232-rs485-rs422/

You should be able to find one local, just make sure it has a breakout board... that will make it easier to wire up

This means that In your opinion RS422 protocol is in device side (flow meter) ?
i Already use rs485 to rs232 and ttl to rs232 converter but can not receive an response of device to my laptop in hyper terminal !
How can I Exactly find following in device side (that have 4 pins) ?
tx , rx , gnd

mohammad2060 said:

This means that In your opinion RS422 protocol is in device side (flow meter) ?

Click to expand...

Yes, to me that would be correct

mohammad2060 said:

How can I Exactly find following in device side (that have 4 pins) ?
tx , rx , gnd

Click to expand...

I would think that is half duplex RS422 so your top and bottom is your TX and RX

Again this is just a guess... have you contacted the manufacture? or they may have more information on their website

I haven't talked to an aquamaster for a while, but from memory you need to send a couple of carriage returns (i.e. hit enter a couple times) to wake up the transmitter. It will then send you messages in ascii and you send back commands using single characters. Very simple. The port settings are 4800 baud, 8 data bits, can't remember the rest but it should be in the manual.

Just a small point to make guys...

mohammad2060 said:

...I do not know which type of protocol...

Click to expand...

geniusintraining said:

...Looks like a RS232 to RS422 adapter...

Click to expand...

mohammad2060 said:

...This means that In your opinion RS422 protocol is in device side (flow meter) ?...

Click to expand...

geniusintraining said:

...Yes, to me that would be correct...

Click to expand...

Saffa said:

...It will then send you messages in ascii...

Click to expand...

ASCII is the first mention of a "protocol" here.

RS-232, RS-485, RS-422, etc., are all data transmission Standards. They define the electrical characteristics and timing of signals, the meaning of signals, and the physical size and pin-out of connectors. They are not protocols.

A protocol defines the syntax, semantics, and synchronization of the data being transmitted by the transmission Standards.

I thought it very important to make that distinction here.

---------------------------------------------------------------

It always helps to post the catalog, model, or code number of the product you are seeking assistance with.

For instance, this datasheet for an AquaMaster 3 Electromagnetic flowmeter is littered with references to the MODBUS protocol using the RS-485 Standard...


...and here is the MODBUS Tables Supplement for the AquaMaster 3.

But this may, or may not be what you have?

Regards,
George

Have you tried using the ABB "CalMaster2" software?

http://www05.abb.com/global/scot/scot203.nsf/veritydisplay/cd85cd3483af16e9c1257a860042b5a7/$file/IM_VCM2_H.pdf

It looks to me like TTL which would make the cable a TTL to RS232 converter. If that’s the case then it must be using one of the handshaking lines to power the conversion. TTL is a “0 = low / 2.5+ = high” communications standard and RS232 is a “-3 to -25 = low / +3 to +25 = high” communications standard. Most PC serial ports need to see at least -5/+5 to operate. I’d guess that one of the 3.5 volt pins and the 0 volt pins along with the ground are the communications lines and the other 3.5 volt pin is the handshaking line.

Firejo
i test ttl to RS232 converter and rs485 to rs232 converter but can not connect to device , Of course my supply voltage was 7 volt in ttl to RS232 converter .
I agree with you about the handshaking line.

in your opinion , can solve my problem The following device ??
https://www.campbellsci.com/sc32b-overview

or isolated full duplex RS232C interface Can not solve my problem ؟؟


Geospark
my AquaMaster is AquaMaster 's' model that is different from AquaMaster 3. AquaMaster 's' is an older model

Unfortunately I don’t have any working knowledge of Aquamaster equipment so I can’t comment on the solution you are asking about. I just saw the diagram you posted with the voltage levels and realized that it looks like TTL. Given that there is a cable out there somewhere then there should be a way to duplicate it. With that said, the first thing you would need to know, assuming that my observations are correct, is which line is the communication line and which one is the handshaking line. It also seems very odd to me that there is only one handshaking line. Usually if there is an RTS or CTS line, you get the other one as well. Same with DSR and DTR. With this only having one handshaking line (again an assumption) I think it’s possible that the handshaking line is being used as a clock pulse or something like that. I know that Allen Bradley’s “PIC” protocol, while using a serial port on a PC, does use one of the handshaking lines like a clock pulse. I don’t know what its real purpose is I just know that if I scope it I see it pulsing (very fast). This could be nothing more than a means of waking the port up but it is required when connecting to a “PIC box” for programming early SLC’s. I think your best bet is to try and find one of the cables that was made to do what you are trying to do.

Give your ABB rep a call. They can supply you a cable I'm sure. Although they are never cheap for what they are!

Firejo
i use ttl to rs232 converter with max232
As botton pin (handshaking line that is an assumption) is for vcc and The following result appeared on hyper terminals .
Each character that you see below is obtained by pressing tab button.


this device works like this that with Press tab button (Thrice) , Settings page device appears. but Not mean this results .
in your opinion , Why obtained this results ???
Does anyone know what this characters ???


When I use a separate power , Writing connected pc and device but No effect tab button !?