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Tom OD

Mesu not tracking on initial testing

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17 minutes ago, Tom OD said:

So I wonder could I use something like this. I could plug the USB cable from the Eagle / PC into the board, then take an RJ11 cable cut one end and wire it to the Green connector on the board, then plug the other end into the RS232 on the mount.

I can't think of any reason why not.

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Just now, steppenwolf said:

I can't think of any reason why not.

Its description did say RS485, which should not matter if I m just matching pins to pins. Now I start wondering why a serial D style connector has electronics in it for its output. What are those electronics doing?

Anyway that's for me to research / Google.

Tom

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2 hours ago, Tom OD said:

Its description did say RS485

OK, so this isn't a USB to RS232 adaptor with screw terminals then? I don't know enough about the difference in protocol between RS 232 and RS 485 only that the latter can be used over a greater length - be careful not to add another variable! It just clouded over, the dome has closed so I'm off back to bed!

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Tom.

If I remember correctly RS485 uses differential amplifiers in the transceivers for the RX and TX signals so Rx has it’s own separate 0v and Tx has it own 0v, they can’t share a common 0v on the signal pairs.

The Sitech is RS232 and RS232 uses end-to-end cabling and doesn’t use differential amps so you only need three wires, Rx, Tx and a common 0v (and maybe +5v if the receiver amp in the device is not host powered).

Besides the above, the logic levels are different with RS232 working at either 5v or 15v and RS485 working at 6v, finally, RS232 uses simplex or full duplex modes and RS485 only uses simplex or half duplex.

Bottom line is that in very few cases can RS485 be directly substituted for RS232 unless the port hardware is either user or auto detect configurable and the full set of cabling is provided.

Looking at the Sitech drawings and manual this appears to be an RS232 only device.

HTH.

William.

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7 hours ago, Oddsocks said:

Tom.

If I remember correctly RS485 uses differential amplifiers in the transceivers for the RX and TX signals so Rx has it’s own separate 0v and Tx has it own 0v, they can’t share a common 0v on the signal pairs.

The Sitech is RS232 and RS232 uses end-to-end cabling and doesn’t use differential amps so you only need three wires, Rx, Tx and a common 0v (and maybe +5v if the receiver amp in the device is not host powered).

Besides the above, the logic levels are different with RS232 working at either 5v or 15v and RS485 working at 6v, finally, RS232 uses simplex or full duplex modes and RS485 only uses simplex or half duplex.

Bottom line is that in very few cases can RS485 be directly substituted for RS232 unless the port hardware is either user or auto detect configurable and the full set of cabling is provided.

Looking at the Sitech drawings and manual this appears to be an RS232 only device.

HTH.

William.

Thanks William,

3 wire with no amp sounds like the easier way to go then.

PrimaLuce got back to me to say that the USB3.0 is on a different board to the USB 2.0. So unless the issue is a common internal passing of the comms from both boards, that would seem to rule out the Eagle. "Seem" at least, not ruled out yet.

Tom

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Tom, have you tried using a different USB cable yet?

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7 hours ago, Oddsocks said:

Bottom line is that in very few cases can RS485 be directly substituted for RS232 unless the port hardware is either user or auto detect configurable and the full set of cabling is provided.

Looking at the Sitech drawings and manual this appears to be an RS232 only device.

Thanks for the confirmation, William.

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Tom

If you are looking at moving to a RS232 input to the SiTech 2 board SiTech can supply a cable. I had some issues early on with USB cables and soldered up a Serial cable myself but I could not get it to work. Taj at Sitech made one up to the length I required and it worked first time and there has not been a glitch since. There are different types of chip-set in the USB to Serial converters, some work and some don't. When using the RS232 input there is a jumper that needs to be made on the PCB board to activate 232 mode. It is to the left of the three LED`s at the top of the board. See diagram.

It may be worth contacting Sitech direct as they may be able to give advice as to if they have come across your problem before. They are usually pretty quick to respond to queries.

Graham

PCB3.JPG.e2629fea0292d3692c264ee73e7323c2.JPG

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Posted (edited)
2 hours ago, Tom OD said:

Thanks William,

3 wire with no amp sounds like the easier way to go then.

PrimaLuce got back to me to say that the USB3.0 is on a different board to the USB 2.0. So unless the issue is a common internal passing of the comms from both boards, that would seem to rule out the Eagle. "Seem" at least, not ruled out yet.

Tom

I wouldn't rule it out yet.  If at all possible just try it on another PC as I had no end of USB problems and they all fell on deaf ears and the solution was sending my Eagle 2 Pro back, and reverting to my mini PC, and not a single issue since.

Worth a try just to rule out the seemingly unlikely.

Edited by RayD

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Posted (edited)

Just for reference on the Eagle2, they are an Intel NUC with the 4 USB 3 ports being part of the NUC, and the 4 USB 2 ports being on a separate board, along with the power ports and dew heaters, which is made by PLL and connects via a USB header on the NUC.

Edited by RayD

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2 minutes ago, RayD said:

I wouldn't rule it out yet.  If at all possible just try it on another PC as I had no end of USB problems and they all fell on deaf ears and the solution was sending back my Eagle 2 Pro going back to my mini PC and not a single issue since.

Worth a try just to rule out the seemingly unlikely.

 I had a similar issue with my Mesu and Eagle (first gen). After a few weeks of agonizing over this, I switched to a Pegasus UPB and a regular tower PC and never had this problem again. 

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8 hours ago, PhotoGav said:

Tom, have you tried using a different USB cable yet?

 

6 hours ago, Fellside said:

Tom

If you are looking at moving to a RS232 input to the SiTech 2 board SiTech can supply a cable. I had some issues early on with USB cables and soldered up a Serial cable myself but I could not get it to work. Taj at Sitech made one up to the length I required and it worked first time and there has not been a glitch since. There are different types of chip-set in the USB to Serial converters, some work and some don't. When using the RS232 input there is a jumper that needs to be made on the PCB board to activate 232 mode. It is to the left of the three LED`s at the top of the board. See diagram.

It may be worth contacting Sitech direct as they may be able to give advice as to if they have come across your problem before. They are usually pretty quick to respond to queries.

Graham

PCB3.JPG.e2629fea0292d3692c264ee73e7323c2.JPG

Thanks Graham this is very useful info. I presume the jumper is already on the board, just at an unused position. I'll chat to Sitech about the cables if I struggle with the soldering iron :)

5 hours ago, RayD said:

I wouldn't rule it out yet.  If at all possible just try it on another PC as I had no end of USB problems and they all fell on deaf ears and the solution was sending my Eagle 2 Pro back, and reverting to my mini PC, and not a single issue since.

Worth a try just to rule out the seemingly unlikely. 

Absolutely worth the effort to rule out the PC, Thanks Ray.

Next steps are:

1) Swap out the USB cable.

2) Use a different PC to test the SiTech USB connection.

3) Switch to RS232 port with new cable and jumper installed.

4) Use a separate power supply up to 13v to power the Eagle.

5) Get my hands on a large bin, and calmly put all the broken bits into it.

6) After a deep breath, install separate power supply from step 4 to power mount. Use a new Power pack, maybe the Pegasus it has good feedback, then use a new Mini PC/ Laptop /Tower

7) Go back to the bin fish out the Eagle, and use it to focus, operate the camera and change filters on a second scope on the rig to go dual.

 

Step 7 may be wishful thinking, but I m trying to stay positive.

Thanks for everyone's  input to this thread.

Tom

 

 

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6 hours ago, RayD said:

Just for reference on the Eagle2, they are an Intel NUC with the 4 USB 3 ports being part of the NUC, and the 4 USB 2 ports being on a separate board, along with the power ports and dew heaters, which is made by PLL and connects via a USB header on the NUC.

This is good to know Ray thanks for the info. The header you mention could be an issue two as its common I guess

Tom.

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Tom

Yes the jumper is pushed onto one pin, not bridging the pins.

For a remote/automatic setup I decided to sell my Pegasus and go for an industrial powered USB hub on the mount and run Switching, Weather etc with the Dragonfly which I already had. At the time it wasn't possible to control the features of the Pegasus using scripts (it may be possible now) so I didn't see the point. Maybe the Eagle is different.

Keep it Simple St!!!! (as you Can) 🙂

Hopefully SiTech may have an answer.

Graham

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On 02/01/2019 at 19:43, steppenwolf said:

..... and an independent confirmation - note the warning in red:-

sitech_controller_4_pin_2.png.9ec45b2fa809a26642232e5357a9d9c3.png

Hi Steve, and anyone else reading this.

I am about to solder the USB to the RJ11, but I m still a little confused about the diagram above. I can read it about 3 different ways. The arrows are in opposite direction suggesting the direction of the data. Yet both arrows say from the Host. is the Host the PC, or the Mesu. I presumed the PC.

Reading from left to right I took the pin signal that I need to send to the RS232 port as 5v, Grd, Tx, Rx. Would you mind checking the pics, and let me know if you think its correct?

Thanks Tom.

USB labeled.jpg

Wiring for RJ11 to Mesu RS232.jpg

Wiring prior to solder.jpg

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Hi Tom.

Not quite sure what you are doing here, you can't cut the end off a standard USB cable and connect it directly via a RG11 to the RS232 port on the MESU.

Windows will never recognise the MESU as a RS232 port, the USB port hardware on the host computer will only recognise and configure standard USB devices.

You must use a USB-to-RS232 port emulator/adaptor and connect the emulator/adaptor to the MESU.

Something like this, preferably using a FTDI UART chip with COM retention, USB-to-RS232 emulator:

https://www.amazon.co.uk/StarTech-com-USB-Serial-Adapter-Powered/dp/B004ZMYTYC/ref=sr_1_1?ie=UTF8&qid=1549930141&sr=8-1&keywords=1+port+ftdi+usb+to+serial+rs232+adapter+cable+with+com+retention

You will also need a re-wireable DB9 connector, with shrouds, to connect the RS232 emulator/adaptor cable to the RJ11 plug.

https://www.amazon.co.uk/Serial-Connector-Removable-Plastic-Housing/dp/B00KDBXD3W/ref=sr_1_fkmr1_1?ie=UTF8&qid=1549930766&sr=8-1-fkmr1&keywords=rewireable+db9+female

I've linked to a Startech RS232 emulator/adaptor above as these were the make I used to use at work and proved reliable, though expensive. You can find cheaper makes that use FTDI UART's but avoid Prolific UART's there are so many fake Prolific UART chipped devices out there and many prove unreliable. The latest FTDI UARTS use COM port retention so once Windows has recognised it and registered the COM port even if you move the USB plug to a different USB socket on the computer the port number in software does not change.

HTH

William.

*EDIT* Note, see appendix D of the Sitech manual (page 47) for wiring diagram of the RS232 port DB9 plug to Sitech RJ11 plug, also, you do not require or connect the 5V pin, only RX, TX and 0v are used.

Edited by Oddsocks
added note

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Hi Tom, William is quite correct here, you do need an RS232 port on your PC (if it has one, it will be a 9 pin ‘D’ shaped port with a 5 and a 4 row set of pins) however unless your PC is elderly, it won’t have such a port and this is where William's timely advice on a USB to RS232 adaptor comes to the rescue. Definitely do NOT adapt an exiting USB cable or disaster will ensue!!

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17 hours ago, Oddsocks said:

Hi Tom.

Not quite sure what you are doing here, you can't cut the end off a standard USB cable and connect it directly via a RG11 to the RS232 port on the MESU.

Windows will never recognise the MESU as a RS232 port, the USB port hardware on the host computer will only recognise and configure standard USB devices.

You must use a USB-to-RS232 port emulator/adaptor and connect the emulator/adaptor to the MESU.

Something like this, preferably using a FTDI UART chip with COM retention, USB-to-RS232 emulator:

https://www.amazon.co.uk/StarTech-com-USB-Serial-Adapter-Powered/dp/B004ZMYTYC/ref=sr_1_1?ie=UTF8&qid=1549930141&sr=8-1&keywords=1+port+ftdi+usb+to+serial+rs232+adapter+cable+with+com+retention

You will also need a re-wireable DB9 connector, with shrouds, to connect the RS232 emulator/adaptor cable to the RJ11 plug.

https://www.amazon.co.uk/Serial-Connector-Removable-Plastic-Housing/dp/B00KDBXD3W/ref=sr_1_fkmr1_1?ie=UTF8&qid=1549930766&sr=8-1-fkmr1&keywords=rewireable+db9+female

I've linked to a Startech RS232 emulator/adaptor above as these were the make I used to use at work and proved reliable, though expensive. You can find cheaper makes that use FTDI UART's but avoid Prolific UART's there are so many fake Prolific UART chipped devices out there and many prove unreliable. The latest FTDI UARTS use COM port retention so once Windows has recognised it and registered the COM port even if you move the USB plug to a different USB socket on the computer the port number in software does not change.

HTH

William.

*EDIT* Note, see appendix D of the Sitech manual (page 47) for wiring diagram of the RS232 port DB9 plug to Sitech RJ11 plug, also, you do not require or connect the 5V pin, only RX, TX and 0v are used.

Thanks William,

I had clearly gone down the wrong path here. I thought that by using the jumper on the Mesu board, that this would act as the emulator for the USB signals to

convert them to RS232.

Thanks for these links. I 'll make sure to get the FTDI UART type electronics. I need to review that wiring diagram too. There is no problem obtaining a D style connector to wire to the RJ11.

Tom.

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10 hours ago, steppenwolf said:

Hi Tom, William is quite correct here, you do need an RS232 port on your PC (if it has one, it will be a 9 pin ‘D’ shaped port with a 5 and a 4 row set of pins) however unless your PC is elderly, it won’t have such a port and this is where William's timely advice on a USB to RS232 adaptor comes to the rescue. Definitely do NOT adapt an exiting USB cable or disaster will ensue!!

Thank Steve,

Yes I went very wrong with this :(

I don't have a serial D style connector so I'll get the USB to serial connector, as per William's specs. The soldering is something I will do myself.

Tom

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6 hours ago, Tom OD said:

Thank Steve,

Yes I went very wrong with this :(

I don't have a serial D style connector so I'll get the USB to serial connector, as per William's specs. The soldering is something I will do myself.

No problem, Tom, at least you are now on the right track.

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