My company manufactures (and I do service for) a process monitoring device for Heat Treating. The PLC we have been using has been obsoleted by its manufacturer, and I'm looking for something to simplify this device.

What I would like to find is something that would allow the I/O devices to directly connect to the PC, with as little in between as possible.

The inputs I would need would be at least one frequency counter, a 0-10vdc, and a maybe half a dozen other yes/no type inputs.

For Outputs, I think all I will really need are some relay style contacts.

My experience with this type of equipment is limited, but usable, so please bear with me.

 

Check out Opto22...

 

Advantech 6051 - $195
Digital Input - Channels: 12
Counter Input - Channels: 2 (32-bit + 1-bit overflow)
Frequency range: 0.2 ~ 4500 Hz (frequency mode)

Advantech 6060 and 6066 - 6 DI, 6 Relays. $210 to $225

Advantech 6017 - 8 AI / 2 DO. Input type: mV, V, mA. $315

I don't know your application in detail, so I'm not specifically recommending the above items for it. This is just to show you examples of what is available. There are other similar products from other companies. There are also rack style I/O modules from numerous sources (for Advantech, racks are in their 5000 series). If I were using the above listed items though, I would add some sort of additional signal isolation and protection between the modules and the field devices

These communicate with a PC via Ethernet. You would plug the I/O modules into an Ethernet switch, and then plug the switch into the PC. You can use Modbus/TCP, which is the closest this industry has to a standard open protocol (most other protocols are vendor specific). You can also use Advantech's UDP ASCII protocol. It is fully documented and very easy to use.

There are USB I/O modules, but I would avoid these as I don't think these are robust enough for industrial use. They also don't have a long product life, so you would end up constantly sourcing different USB modules, which would be
a customer support headache.

There are other communications media besides Ethernet, such as Devicenet, Profibus, etc. I would avoid those however. You typically have to plug a special (and expensive) proprietary board into the PC to use them, so they aren't as nice from a service or support standpoint.

 

I would suggest ADAM Remote I/O
http://www.advantech.com/eAutomation/Remote-IO/

and Modbus for communication.

 

Hi,

You could see and test the Sixnet products as well. They have Ethernet I/O modules called "EtherTRAK Ethernet I/O" which support Modbus TCP/IP as protocol (the best choice).

Here you can see their main features and models:
http://www.sixnetio.com/html_files/products_and_groups/io_ethertrak.htm#select

and here their prices:
http://www.sixnetstore.com/Merchant...=CTGY&Store_Code=im1&Category_Code=EthernetIO

I have used Advantech and Sixnet products and both of them are excellent. Of course, you will need later an external device (RTU/PLC or PC) to control/run your logic and read/send command to plant through these kind I/O modules.

Best regards.

Saludos.

Gustavo A. Valero P.
BIConsulting C.A.
Valencia - Venezuela
gustavo.valero @ biconsulting. com

 

I've used the ADAM modules from Advantech for many years, over 2 wire RS485. With a USB to RS485 module, you can have all your IO devices hanging off 2 wires. If the wires are long (> 10 metres) use a lower baud rate. 9600 baud.

 

Opto22 gets my vote as well, the sort of system you describe would be < $2000. Their software is free/cheap depending on the features you require and easy to use, Flow Chart (not ladder). You need to be careful with discrete outputs, the dry contacts are only rated for fraction of Amp but they have Solid State as well.

Good Hunting,
Roy