Hi guys,

I want to control Helvar lights but the Helvar RS232 interface is powered by the
DTE RS232 port by seting the RTS/DTR lines HIGH.

Any idea wether the RFX9600 rs232 port supports this and how it is done?

I could make a cable connection and power the interface from an external regulated supply as last resort...


Thank you,

Sorin

There's a +5V output on back of RFX9600. In fact, you should see the prep materials for Level 2 certification on Philips site as it specifically discusses this output. You should be able to wire something up that way. I'd do this instead of a separate regulated supply.

With regard to RS232 on RFX9600, they use Pins 2, 3, and 5 (RX, TX, and GND).

Thank you Lyndel. You're right. I am using the 5VDC supply with an video sensor. I wasn't sure if it is a regulated voltage.

If their RFX9600 rs232 port has got only pins 2,3&5 connected then how are they thinking to control devices that require hardware flow control?
If I am not mistaking, one would have to make connectors with handshake lines looped back so that the equipment controls its own handshaking.

You are correct, with only pins 2,3, 5 connected you can not do hardware flow control.

In theory you are correct in that if the device (component) was truly RS232 compliant then they would need to have DSR (Data Set ready) asserted to receive and CTS (Clear to Send) asserted to send. In a loopback situation generally DTR is used as the assertion source and tied to CTS and DSR.

In todays Micky Mouse shortcut world, many RS232 devices are really not RS232 but serial transmission devices using a physical layer similar to that of RS232, but not necessarily the same (e.g. +/- 12 volt swings with 6 volts of hysterises {i.e. -3 to +3 is "undefined" as to logic state). Many use +12 and ground, some use +5 and ground, some . . . The decent ones do obey the physical layer using RS232 driver receiver chips, but do not implement the specified control signals.

Hi Barry,

As I am not very experienced, I guess that I expect equipment to comply to standard protocols as documented.
Thank you for furthering my knowledge on this topic.

Kind regards

Sorin

Always my intent.

The DB9 connectors (there are 3 on the RFX9600) may indeed use the other signals but for sure the Phoenix connect used for RS232 #4 is truly 3 Pin only.

Easiest way to figure this out is to test.