help regarding serial communication

[vijay shankar]

hi everyone,

i am new to labview and i am from computer science department.. i didnt have any idea about labview a few days back.. but a conventional computer science programmer familiar with other programming languages..

i need to develop a project in labview to access a controller ( a TEC controller in my case) from my machine..

I have a serial port in the controller, but i dont have any adapter for that..

I need to develop the program in an XP system and so i just need an idea of how to go about this project.

I basically have the following questions,

1. to connect the controller to my system, do i need a rs232 cable (from the company?).

if so, do i need a PCI card installed in the system? any specific card?

or can i have a rs232 to usb adapter and plug that into my system and still develop my project in labview?

2. to program in labview, should i need a instrument driver to send commands to the controller?

if there is something of this sort, then what should i get from the vendor who supplied the controller for me..

to be specific, the controller is a series 800 thermaoelectric cooler controller from alpha omega instruments

[Minh Pham]

QUOTE (vijay shankar @ Nov 1 2008, 12:49 PM)

I have a serial port in the controller, but i dont have any adapter for that..

I need to develop the program in an XP system and so i just need an idea of how to go about this project.

I basically have the following questions,

1. to connect the controller to my system, do i need a rs232 cable (from the company?).

if so, do i need a PCI card installed in the system? any specific card?

or can i have a rs232 to usb adapter and plug that into my system and still develop my project in labview?

2. to program in labview, should i need a instrument driver to send commands to the controller?

if there is something of this sort, then what should i get from the vendor who supplied the controller for me..

to be specific, the controller is a series 800 thermaoelectric cooler controller from alpha omega instruments

You do need a serial cable to connect the device to the PC, i think a normal RS232 cable is fine as long as the device has a

D-SUB 9 pin RS-232 at the back (i believe it has according to the specs i found through its website.)

You dont need any PCI card for this as serial communication is enough to control and receive msgs between the PC and the device.

RS232 to USB should be fine but if you can use the straight serial to serial cable as it is simple and cheaper that way i reckon.

VISA driver from NI-VISA APIs should be enough for you to control this device if this device accept this way of communication. However I

did have a look at the specs, it seems like the device using MODBUS protocol for communication with PC, so it is a good time to search around

for some MODBUS vis or library for labview and learn it. If you really into it, i suggest you can write your own vis for this communication as it will help you understand LabVIEW as well as MODBUS communication.

After you've done with the communication task. YOu are pretty much set for do whateva u like with the temperature controller, you can SET temperature, GET temperature, etc... by sendding data/commands or syntax through your communication vis to set a certain modbus registers...

Good luck

[jdunham]

QUOTE (Minh Pham @ Nov 2 2008, 04:15 PM)

You dont need any PCI card for this as serial communication is enough to control and receive msgs between the PC and the device.

RS232 to USB should be fine but if you can use the straight serial to serial cable as it is simple and cheaper that way i reckon.

I think the OP meant that his computer doesn't have any serial ports. RS232 to USB should work fine, but a PCI card will be fine too. Often your motherboard will have the RS232 header on it, so you just need the extender cable to the back of your chassis, which you could find at a surplus store. Either way, you should be able to get an RS232 port for US$20-25 (unless you buy it from NI).

[jgcode]

QUOTE (Minh Pham @ Nov 3 2008, 07:15 AM)

VISA driver from NI-VISA APIs should be enough for you to control this device if this device accept this way of communication. However I

did have a look at the specs, it seems like the device using MODBUS protocol for communication with PC, so it is a good time to search around

for some MODBUS vis or library for labview and learn it. If you really into it, i suggest you can write your own vis for this communication as it will help you understand LabVIEW as well as MODBUS communication.

Different from the Modbus IO server, there is a Modbus Library available here thru NI as well as info in this KB. I have used this for serial comms successfully in the past.

[Minh Pham]

QUOTE (jgcode @ Nov 3 2008, 03:32 PM)

Different from the Modbus IO server, there is a Modbus Library available here thru NI as well as info in this KB. I have used this for serial comms successfully in the past.

Surprisingly there are many aussies in this site ! :beer:

and surprisingly the questionee is not comming back to his/her thread

[jgcode]

QUOTE (Minh Pham @ Nov 4 2008, 11:30 AM)

Surprisingly there are many aussies in this site ! :beer:

and surprisingly the questionee is not comming back to his/her thread

Right back atchya! :beer:

[crelf]

QUOTE (Minh Pham @ Nov 3 2008, 10:30 PM)

Surprisingly there are many aussies in this site ! :beer:

It's a quality forum! :beer:

[jgcode]

QUOTE (crelf @ Nov 8 2008, 02:53 PM)

It's a quality forum! :beer:

That deserves another beer :beer:

[crelf]

QUOTE (jgcode @ Nov 8 2008, 04:32 AM)

That deserves another beer :beer:

I'll drink to that :beer:

PS: on my recent trip downunder, I wasn't able to get to my home state (New South Wales), but I was thankfully able to find my favorite beer (Tooheys Old) on draught in Melbourne. The bar chick told me that you can get both Tooheys Old and Extra Dry on tap all over Melbourne now - it's good to see that Victorians are starting to come to their senses...

[jgcode]

QUOTE (crelf @ Nov 10 2008, 12:40 AM)

I'll drink to that :beer:

PS: on my recent trip downunder, I wasn't able to get to my home state (New South Wales), but I was thankfully able to find my favorite beer (Tooheys Old) on draught in Melbourne. The bar chick told me that you can get both Tooheys Old and Extra Dry on tap all over Melbourne now - it's good to see that Victorians are starting to come to their senses...

Oooo I used to drink Tooheys Old on tap at Uni and always got strange looks from everyone... they were too young to appreciate the quality of ye dark ale.

So I will drink to that :beer:

[crelf]

QUOTE (jgcode @ Nov 9 2008, 05:22 PM)

Oooo I used to drink Tooheys Old on tap at Uni and always got strange looks from everyone...

OK - thread officially hijacked. I started drinking it at uni too (UTS) because no one else in my dorm would drink it, so it was safe in the common fridge Thankfully I've found similar brews here in the US: Shiner Bock when at NI-Week in Austin and Motorcity Brewing Works Nut Brown when at home in Detroit.