By graphical Windows display, are you inferring seeing all this data on your client's desk's PC?
The easiest way I've found to get a display of multiple digital process values onto the desktop is to use the internal web server in a Honeywell paperless recorder. The recorder sits the plant's LAN.
When the user wants to see the data, he calls up Internet Explorer, clicks on the recorder name in favorites and the recorder's screen with all the digital values pops up on his workstation monitor. Updates live.
The recorder is inherently designed to handle AI's (differential inputs, good isolation and common mode rejection, not the low-end PLC AI's that can be a problem), and has pre-programmed screen layout for digital values.
Some customers like it because they can add points on their own. Yeah, I don't necessarily make money adding points if they do it themselves, but more often than not, they'll ask me to do it when I'm back there for something else. And I don't have pull out the PC with a licensed development program; just wire it up and do a quick touch screen configuration to add the AI point and the value on a display screen.
Plus, there's no HMI license for the PC.
I've also done all these others at one time or another that aren't putting the data directly on the user's PC:
1) One digital panel meter or a single 1/32 DIN controller/indicator for each device. Sometimes the real need is for multiple panels; 16 here, 20 there.
2) PLC/PAC with I/O, HMI panel where ever.
3) Remote AI I/O Modbus/TCP modules on the LAN, HMI panel (Modbus/TCP master) reads the modules and displays the data.
4) Precision Digital has the Minimux II (PD138) that multiplexes 8 AI's to a single digital meter, users have to wait for the reading they want to come around. But it cuts down the cost per AI. There's a particular model for loop powered outputs (transmitters) to prevent powering down the loop when the mux switch is not 'made' for that particular loop.
This is an odd scenario. Thirty-six devices that need to be viewed only? That's a lot of data to take care of manually.
Note that it's not a particularly difficult problem, although with that much analog input it might be expensive. Any I/O module would work, although talking to the I/O module could be tricky. Without more information, it's hard to give exact advice, but I can think of a few different ways to do this.
1) Modular (or "slice") I/O, with a Modbus/TCP front end. Data can be pulled directly to a variety of HMI programs, or to virtually HMI program via a Modbus/TCP OPC server. A custom application could also be written fairly easily. I/O could be Wago, Beckhoff, B&R, AutomationDirect.com, Turck, etc., etc., etc.
2) Analog inputs in the PC. National Instruments is the leader here, although Advantech and many others also compete. Application can be custom, LabView, etc. This is generally called "Data Acquisition," (or DAQ) mostly for historical reasons.
3) Remote DAQ to PC, with NI, Advantech, Red Lion, etc., etc., etc.
Which I would recommend would have more to do with what the customer is familiar with than the technical merits of each option. Also, some more detail on the application would be nice. How far apart are these sensors? How fast do they need to update? Do they need to log the data? Are they planning on eventually using the data as part of process control, instead of just manual intervention?
If what you want to do is reduce the amount of point-to-point wiring, and you want to connect directly to a DCS or SCADA system, Moore Industries (www.miinet.com) produces both analog and HART loop concentrators and distributed I/O modules. There are other suppliers as well.
The Honeywell (formerly Penny & Giles) paperless recorders can do some of the same things. There are other vendors in the paperless recorder business, like aBB, as well.
Walt
Walt Boyes
Life Fellow, the International Society of Automation
Editor in Chief
Control and ControlGlobal.com
555 W. Pierce Rd Suite 301
Itasca, IL 60143
If all 36 devices are in close proximity to each other, a Red Lion Modular Controller works very well. Bring the signals into the analog input modules, configure a screen in their free software, and that screen can be viewed in their built-in web server (I would recommend the full VGA controller) for easier viewing. Control can also be integrated into the system (scaling, alarming, etc.)
If the points are spread out over a large area, Banner's DX80 wireless products accept 4-20 and transmit it to a gateway that can hook up to a Red Lion Data Station that provides the same web server capability as described above. Or you could put the data from the Banner wireless on the "cloud" using a product like Exosite.com.
