frank@dvm.UUCP (03/31/87)
**** Anti-LineEater Pills ******** I am looking for a thermometer which reads out air temperature over a RS-232 port. I would like to use such a device to monitor the temperature in a computer room. Once the thermometer indicates a temperature above a safe maximum, the computer it was connected to could shut down itself and any other computers in the room. I have everything I need to implement this scheme but the thermometer. Does anybody out there know of any? Thanks in advance. -- Frank ...!inhp4!allegra!phri!orville!dvm!frank
larry@kitty.UUCP (03/31/87)
In article <128@dvm.UUCP>, frank@dvm.UUCP (Frank Wortner) writes: > I am looking for a thermometer which reads out air temperature over a > RS-232 port. I would like to use such a device to monitor the temperature > in a computer room. Once the thermometer indicates a temperature above a > safe maximum, the computer it was connected to could shut down itself and > any other computers in the room. I have everything I need to implement this > scheme but the thermometer. Does anybody out there know of any? Contact a company called Omega Engineering, Inc., P. O. Box 4047, Stamford, CT 06907, or telephone 203/359-1660. Omega is a large manufacturer of temperature measurement apparatus; they have a number of products which can solve your problem, but the lowest cost route is probably a combination of P/N 115-TC type-T thermocouple digital indicator whose analog output is connected to a P/N WB-31 analog -> RS-232 interface. The 115-TC is around $ 189.00, and the WB-31 is around $ 495.00. In addition, you will need a type-T thermocouple for around $ 25.00. I have used a less expensive method to accomplish pretty much the same thing. Get a good-quality thermostatic switch with a calibrated dial from an industrial supply house (NOT a home thermostat!); use a vendor like Chromalux or Allen-Bradley. Connect the isolated contacts of the switch to an unused RS-232 port so that reaching the temperature setpoint will assert the carrier-detect lead on the port. Use a simple daemon to scan the RS-232 port for presence of carrier (use a getphys() function or other means to sense the carrier-detect pin); if the pin is on, then you have a temperature alarm. The cost of such a good quality thermostatic switch is around $ 50 to $ 60. <> Larry Lippman @ Recognition Research Corp., Clarence, New York <> UUCP: {allegra|ames|boulder|decvax|rocksanne|watmath}!sunybcs!kitty!larry <> VOICE: 716/688-1231 {hplabs|ihnp4|mtune|seismo|utzoo}!/ <> FAX: 716/741-9635 {G1,G2,G3 modes} "Have you hugged your cat today?"
capshaw@milano.UUCP (04/01/87)
The thermostatic limit switch with on/off output is simple, affordable, reliable, etc. If you do not want to use the rs-232 modem status signals you can use the switch to make or break a path between transmit and received data. State of the switch is indicated by whether you can send characters back to yourself. Whether to use normally open or normally closed signalling depends on your prefered failure modes. -- Dave Capshaw
sewilco@meccts.UUCP (04/02/87)
In article <128@dvm.UUCP>, frank@dvm.UUCP (Frank Wortner) writes: > in a computer room. Once the thermometer indicates a temperature above a > safe maximum, the computer it was connected to could shut down itself and I used the switch from an attic fan. A surplus store in town has dozens of them, each labeled with the temperature at which it closes the circuit. They look like squat cylinders with two wires coming out. I confirmed the 85 degree label with a plastic bag, a glass ofhot water, and a good thermometer. In my case, I used the mouse switch port on an Apple Lisa. Larry Lippman already described how to use modem control lines for the same purpose. If you don't have a spare serial port, consider using the modem control lines on a direct-connect console, printer, or other device which doesn't use those lines. -- Scot E. Wilcoxon (guest account) {ihnp4,amdahl,dayton}!meccts!sewilco (612)825-2607 sewilco@MECC.COM ihnp4!meccts!sewilco It may be the event of the century, but "Supernova 1987A" isn't a good catchword.
wcs@ho95e.UUCP (04/15/87)
In article <128@dvm.UUCP> frank@dvm.UUCP (Frank Wortner) writes: >I am looking for a thermometer which reads out air temperature over a >RS-232 port. I would like to use such a device to monitor the temperature >in a computer room. There's a product called "Sensaphone" which detects temperature and (optionally) humidity and water level problems, and calls you on the phone if something's wrong. Cost is about $199. I've seen it in several catalogs; the one I have within reach is MISCO One Misco Plaza Holmdel NJ 07733 1-800-631-2227 The power control system in one of the labs here is designed to shut off everything, including computers and A/C, if the temperature reaches some level (~120F). Shutting down the A/C is the right move if there's a fire, but it's annoying otherwise; the A/C often dies during weekend power hits, and the temperature rises to 120F, making it too hot to turn on the A/C Monday morning when we notice a problem. The cure has usually been to open the doors and wait a couple hours, until it's cool enough to use the A/C. Really should be an override somewhere. -- # Bill Stewart, AT&T Bell Labs 2G-202, Holmdel NJ 1-201-949-0705 ihnp4!ho95c!wcs
mao@blipyramid.BLI.COM (Mike Olson) (04/16/87)
In article <1374@ho95e.ATT.COM>, wcs@ho95e.ATT.COM (Bill.Stewart) writes: > There's a product called "Sensaphone" which detects temperature and > (optionally) humidity and water level problems, and calls you on the phone if > something's wrong. Cost is about $199. I've seen it in several catalogs; the > one I have within reach is > MISCO > One Misco Plaza > Holmdel NJ 07733 > 1-800-631-2227 a company i worked for in kansas city used the sensaphone for temperature control. it can't switch anything on or off, but it'll call up to four people, in a loop, until somebody calls it back and shuts it off. it's also got two 'alarm condition' terminals. if you're so inclined, you can hack up a connection from the computer to the sensaphone (via an rs-232 terminal line). the computer sends an open square wave down the line when it detects a problem. the sensaphone calls you at home. it's got a cheap little voice synthesizer chip that announces to anyone in the room what's wrong and who it's calling. it's also got a clock that drifts pretty badly, but then, *you* know what time it is when the machine calls you. we were pretty satisfied with it. got me out of bed a couple of times, but it also saved several days' work more than once. mike olson