Hi Chris,
Quote:
I have quite a lot of electronics stuff here, but none of it's RS232 any more! So can't see a way to try Damiens idea, which would be much better than my remaining options:
- fault in Jaycar RS232 cable
- fault in Meade serial cable
- fault in the scope
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This simple test will determine if the Jaycar cable works:
The test only involves the PC and the Jaycar USB to RS232 cable.
Do a looback test on the Jaycar USB to RS232 cable. Do this by shorting out pins 2 and 3 on the DB9 end of the cable.
Download Hercules software:
https://www.hw-group.com/software/he...-setup-utility 3.2.8. Or use another program you are familiar with.
Use Hercules to send some text in Serial tab mode, and if it receives it, all is fine with the Jaycar cable and you can move on to the next bit. It does sound like this cable is working.
You can also hook up 2 PC's together if you have another USB/RS232 cable and PC and test that way.
Another test would be to plug the USB adapter into your PC, then plug the other cable into the adapter but NOT into the scope. Then do the same loopback test by shorting out the correct pins on the end of the cable. That way if you get a text response, you know both cables are working fine and all that is left is to check is the connections to the scope are correct. If so, then you have tested everything up to the scope and will know what works and what does not..
1) Should the sequence matter?
In relation to plugging things in, always connect everything before turning power on to anything. That is the safest way. To my knowledge, Meades don't have a lot of electronic protection circuits.
2) does the Meade RS232 serial cable have any smarts in it, or is it just wires?
Just wires. The Jaycar USB to RS232 adapter does all the work/drivers etc.
The cable that connects between the scope and the adapter is just wires, wired correctly for pin connections.
3) Is damage to the serial port a common occurrence for these scopes?
Not sure how common but when I first got my Meade, I was visual only but when I decided to go astrophotography and start plugging things in to the ports, I had no RS232 comms. My guess is a previous owner somehow did something to damage the RS232 chip(s) on the controller board. I pulled the controller board out, replaced the little SMD RS232 chips and luckily all worked fine afterwards. I still have a few of those chips if it turns out you need any. Will have to verify that it's the same chip for your scope, (size type etc).
You mentioned that the adapter to Meade scope cable worked at one stage, could anything have happened to that cable to damage it?
Have you re inspected that cable and ensured that all connector pins are good and that it is wired correctly, (it should as you have had it working).
Make a new cable?
Use a multimeter etc if need be.
Cheers,
Damien