Technical Issues - PerkinElmer IR Spectrophotometer Communicating?

Your 'classic' PerkinElmer infrared spectrophotometer (580B, 68x, 78x, 88x, 983, 983G) has a serial port, but does it work? It's easy to test. To start, you need a 9 to 25 pin 'modem cable' similar to the following:

http://www.computerplug.com/show_product.php?product_id=CMAT10

Note: Do not use a cable marked 'null modem'

Next, fire up Windows HyperTerminal (look under Accessories Communications) to test instrument communications. It first asks for a Connection Description. Type PE983 or similar and proceed. In the next Connect To dialog, select Direct to Com1 (or another COM port if needed) which grays out the telephone number box.

This brings you to the COM1 Properties dialog shown above. To the best of our knowledge, assuming settings were never changed, baud rates are 9600 for 88x/983 and 4800 for 983G and other models. Set Data bits = 8,  Stop bits = 1, Flow control = Hardware. Click File Properties Settings ASCII Setup and enable Echo typed characters locally so that you see what you type. In addition, set Caps Lock on.  Before proceeding, hit File Save As to keep the changes in Hyperterminal..

Carefully type in the following with each line followed by <Enter>. Don't type the comments!

$RE 0<Ctrl+Q>  ' Free running mode (hold Ctrl key and hit Q).
               '     for 881/882/883 leave out <Ctrl+Q>
$GO 3000       ' Select another value if already set to 3000.
               ' The machine should now slew to 3000; when it
               ' stops you can enter the next line.
$MA            ' Restores manual mode

You should hear the machine slew, and the response in Hyperterminal window should be a series of zeroes. If the test fails, we suggest that you power the spectrophotometer off and on and repeat it at another baud rate. If you made any typing mistakes, you might have to restart the spectrophotometer.

Remote Diagnostics

A user had a major problem communicating with a PE 881 IR spectrophotometer. How could this be diagnosed and (hopefully) fixed without flying to Oklahoma or shippng the 881 to Princeton?

We were able to diagnose the problem remotely via TCP-Com software which assigned the remote real serial port COM1 to virtual serial port COM2 on our computer. To do this, however, we needed the unique IP address of the computer connected to the 881. But it was behind a network and the reported address was useless in identifying the computer on the Internet.

The solution? Dial-up! Connecting via modem gives a temporary IP address independent of the network! We could now diagnose the instrument from Princeton! Ultimately, the problem was an early EPROM revision which did not recognize a documented command. The ultimate lesson here is the usefulness of a dial-up connection in this age of networks and high speed.

Lambda 9 Test

The procedure is as above with these settings: Bits per second = 4800, Data bits = 7,  Parity = Even, Stop bits = 1, Flow control = Hardware. The following line replaces $GO 3000.

Carefully type in the following with each line followed by <Enter>. Don't type the comments!

$RE 0<Ctrl+Q>  ' Free running mode (hold Ctrl key and hit Q).
$PA 1          ' Console page 1 (may not be required)
$PA 2          ' Console page 2           "
$GO 550        ' Select another value if already set to 550.
               ' The machine should now slew to 550; when it
               ' stops you can enter the next line.
$MA            ' Restores manual mode

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