Yes!
First: The supply must be capable of AEBus communication. You can find out if this is the case via the debug menu from the front panel (if your supply has one), by opening up hyperterminal and trying to communicate with it, or, easiest of all, calling AE and giving them the serial number. NOTE: The presence of a serial port on the back of the device does not necessarily mean that it is capable of serial communication!
Second: Even if the supply is AEBus capable, it may not be able to be set to every mode that one would be able to set from the front panel. In my experience, the most significant example is: If your supply has a DeviceNet port, it will be impossible to set the supply into voltage regulation mode while controlling it with the serial port. In other words, if you have a DeviceNet supply and you want to control it via RS-232 for a voltage-controlled process, you're out of luck. AE has confirmed that no DeviceNet enabled supplies support anything other than power-regulation while in host (i.e., RS-232) control mode. Even though you can set it into this regulation mode while in local control.
Third: There are several different flavors of serial connector that may be present on the back of the supply. There's the so-called "standard serial port" which uses an RJ-11 type connector and (possibly present) AEBus ports which may be DB-9 or DB-25. As far as I can tell, the only difference in communicating via the "standard" port versus the AEBus ports is the baud rate. The standard port communicates at 19.2 kbaud whereas the AEBus ports communicate at 9200 baud. The structure of the commands is identical.
On a final, semi-related note: If you do have a DeviceNet supply and wish to not use it, you don't have to supply it with 24V just to avoid an error. Open the supply up and remove the card. You then have to switch a jumper (which would otherwise be jumpered on the exterior part of the DeviceNet card), whose identifier depends on the model of your supply. Call AE and they'll tell you what its label is. Problem solved! (Unless you also want to use voltage regulation via RS-232!)
This man RS485 to RS232 converter - seems to be doing what you are doing and achieving success.
It sounds like Hyperterminal should be capable of proper RTS control.
Best Answer
I am currently using the DTR lead for two designs. Like all RS232 leads, the voltage varies from a minus voltage (unasserted) to a positive voltage (asserted). The voltage range is anywhere from ±3v to ±12v. Frankly, I have never seen a voltage amplitude lower than ±5, and that was from a PC COMM port.
The spec for your device says to power the RS-232 interface using +12v on the DTR (asserted), and -12v on the RTS lead (unasserted), for a total of 24 volts. It says it needs 20 ma. This may or may not be possible depending on the RS-232 interface at the other end.
When I did this, there appeared to be a resistor in series with the line at the other end, which acted as a current limiter. I "harvested" between 5 and 10 mA from the DTR line. Even that caused the voltage to drop a bit.
I suggest testing this out first, by measuring the voltage on the DTR and RTS leads with a multimeter. If they're not -12 volts, you can forgot supplying power this way.
If it is -12v, then put a 1210 Ω resistor across the DTR and RTS leads, assert the DTR line and measure the correspond leads to see if the voltage holds up (+12v). You can assert the DTR line either in software (attribute of the COMM function in the Windows API), or for this test, use a program like RealTerm, which has the ability to control the various handshake leads under the Pins tab in its user interface.
I wouldn't worry about the handshaking; if they are telling you to power their interface this way, then it must not be an issue.