Hello I am trying to change the settings on the cotekSD1500-124 use the RJ-11 port using putty and realterm. I send the inverter commands but am not getting anything back can someone help please. or has anyone already done this. Any help would be appreciated thank you. 

On 2019/11/02 at 5:04 AM, OscarS said:

use the RJ-11 port using putty and realterm.

Are you talking to it via RS-232 at 2400 bps N/8/1 via a suitable USB to RS-232 adapter? It looks like an ethernet port, but is probably not (I don't know the Infinis that well).

[ Edit: I don't know why I thought you were talking about an Infini or compatible machine, clearly it is not. ]

Even if you are getting the CRCs wrong, you should get some NAKss (negative acknowledge) packets back.

Ending the commands with a 0x0D (carriage return)?

The known-good USB to serial adapters use a PL2303 chip.

Edited November 6, 20195 yr by Coulomb

Yes I am talking to it via RS232 at 4800 bauds  N/8/1  using a usb to RS-232 adapter. It is not a Ethernet(I uploaded a picture of the data sheet so you can confirm it)  I do not receive any negative acknowledge from it and I am ending commands with both CR and LF which is stated on the manual as well( I have attached a picture of the instructions again.) I am not sure what I am doing wrong as I am doing as the manual states. Any other information would be appreciated Coulomb. I will also read over the link thank you. 

Sorry, I had the impression somehow that the Cotek was an Infini or compatible. It clearly isn't, so my comments are invalid.

All I can suggest is to try other bit rates (I don't see 4800 mentioned in what you pasted), and ensure that you really are sending both the carriage return and the lifefeed characters. It looks CRCs are not required.