Why Crestron can use USB to RS232 adapter for programmatically control SX20 but notebook cannot?

[Chris Tsai]

Why Crestron can use USB to RS232 adapter for programmatically control SX20 but have com port notebook cannot(use Putty and hypertrm)?

I try speed 9600,38400,115200,but Putty and hypertrm is no report and cannot enter the function key .

Can i use USB to RS232 adapter connect SX20 like MXP? have any questions is the need to pay attention to it?

[Danny De Ridder]

Is this a document or a question? When using a USB to DB-9 cable, the DB-9 async connection presents itself as a DTE.

If you take your notebook and another USB to DB-9 cable, that will be a DTE too. To connect both, you would need a null-modem or a cable which presents itself as a DCE. I assume the cabling you have to connect the Crestron has the appropriate layout, whilst your notebook does not.

[Chris Tsai]

Dear Danny

Thank you for your reply

So how can i do to use USB to RS232 control the SX20 like laptop connected USB to RS232 adapter to control as MXP ?(same setting,not telnet)

[Danny De Ridder]

So you have a laptop with some cable which hooks up to the MXP and can control the latter? When I look at the following manual http://www.cisco.com/en/US/docs/telepresence/endpoint/mxp-series/f9/user_guide/mxp_codec3000-6000_physical_interface_guide.pdf I see that this type of MXP has a DB9 female port named data 1 and data 2. Does your MPX also have a female DB9 connector? That kind of interface is a DCE. If you use this same cable from your laptop combined with a USB to DB9 cable on SX20, you would have 2 DTEs connecting to eachother. That does not work. So you need a null-modem for DB9 in-between. http://www.aggsoft.com/rs232-pinout-cable/nullmodem-db9-to-db9.htm

And on SX20 use something like this : http://www.cablestogo.com/product/26886
Then you would have DTE from SX20, DTE from your laptop with DB9 male connectors, and then you put in the null-modem cable which has 2 female DB9s.