If you are having no success with bus communications, check to be certain that the correct bus (EIA-232 or GPIB IEEE-488) is selected using setup parameter F2.

SI (Immediate Mode) or the default SP (Program Mode) are typically issued at the beginning of a program sequence. However they may be issued at any point. If the C4 receives a SI command and there is a command executing and/or commands in the command buffer, the executing command is interrupted and the command buffer is cleared.

The Aux/Power ON (TO) and Aux/Power OFF (TF) commands control the auxiliary power control port. This port is normally used to control power to the chamber or platform or an optional device. It is not necessary to use these commands to enable and disable temperature control.

EIA-232 Problems

EIA-232 issues are usually communications interface related. The C4 is configured as DCE (Data Communications Equipment). Therefore, it is not appropriate to use a crossover or “null modem” cable. Use a straight-through cable that does not have pins 2 and 3 reversed. The C4 does no hardware or software handshaking. DTR and CTS are constantly asserted by the C4 for compatibility with devices that need these signals. Hardware handshaking from the controlling device is ignored. Software handshaking will be parsed as data by the C4 and will reliably result in failure.

GPIB IEEE-488 Problems

C4 status requests are available either via the manual RS (read status) command or by enabling SRQ with the ES command and then using serial poll to obtain the status byte. The serial poll method will only return the status byte after SRQ is enabled with an ES command.

9.7.8 Firmware Upload Problems

Firmware upload is very straight forward and has no options except for the user to select a COM port on the PC. If the upload never starts after the PC program is started, try turning the controller off and then back on and reinvoking rS LOAd mode. Depending on the behavior of the COM ports on the two devices, some experimentation may be in order as to which device needs to be brought up first.

If your uploads appear to run properly and the upload software indicates a successful result, yet the system will not run, you should try the load again. It is

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Sigma C4 manual Firmware Upload Problems