# Any successful RS232 Serial control of a projector via a Mac?



## Mark Neisser (Oct 14, 2015)

I have been bashing my head against the wall trying to control any of my 15 projectors via serial commands and my macbook pro.

I am using a USB serial interface with CoolTerm and a cross over serial cable. I see the usb serial driver and looping back pin 2 & 3 shows the exact hex code that should work coming back from the pin. However it doesn't work to turn on the projector.

Power on cmd is: 
0x06 0x14 0x00 0x04 0x00 0x34 0x11 0x00 0x00 0x5D 
but tech support said to run it as:
06 14 00 04 00 34 11 00 00 5D

Anyone doing this successfully on a Mac with any projector. View Sonic said they didn't have one to test it on!!!

Help me Obewon Kanobee, you're my only hope!!!!


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## Chris15 (Oct 14, 2015)

Have you got your RS232 pinouts correct?
TxD and RxD swapped are one of the banes of my existence with contractor installations.
If you've got a multi meter, you are looking for -15 ish (anything over 5 is a good start) volts on pin 2 and 3 with respect to pin 5.
Off the top of my head I can't remember which is TxD and which is RxD, but if you unplug the connectors and have voltage on the same pin of both connectors it's wired wrong, you should have the voltage on pin 2 of one of the connectors and pin 3 of the other if that makes any sense.


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## Mark Neisser (Oct 14, 2015)

Chris15 said:


> Have you got your RS232 pinouts correct?
> TxD and RxD swapped are one of the banes of my existence with contractor installations.
> If you've got a multi meter, you are looking for -15 ish (anything over 5 is a good start) volts on pin 2 and 3 with respect to pin 5.
> Off the top of my head I can't remember which is TxD and which is RxD, but if you unplug the connectors and have voltage on the same pin of both connectors it's wired wrong, you should have the voltage on pin 2 of one of the connectors and pin 3 of the other if that makes any sense.


Have you gotten it to work on a Mac?


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## Mark Neisser (Oct 14, 2015)

Chris15 said:


> Have you got your RS232 pinouts correct?
> TxD and RxD swapped are one of the banes of my existence with contractor installations.
> If you've got a multi meter, you are looking for -15 ish (anything over 5 is a good start) volts on pin 2 and 3 with respect to pin 5.
> Off the top of my head I can't remember which is TxD and which is RxD, but if you unplug the connectors and have voltage on the same pin of both connectors it's wired wrong, you should have the voltage on pin 2 of one of the connectors and pin 3 of the other if that makes any sense.


My pin set up seems odd. There is NO GROUND (no tone on pin 5 from ANY PIN) that connects and my pin out set up seems strange.


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## Mark Neisser (Oct 14, 2015)

Mark Neisser said:


> My pin set up seems odd. There is NO GROUND (no tone on pin 5 from ANY PIN) that connects and my pin out set up seems strange.View attachment 12552


OK, so now I think the pin out may be correct, but the volt meter on 2 gives me nothing. Is the current sent all the time or only when data is sent?


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## FMEng (Oct 16, 2015)

For troubleshooting RS232, there are two things I routinely do. First, get yourself a "null modem." It's an adapter with a DB9F and DB9M. All it does is swap pins 2 and 3, but it allows a quick test to see if the cable doesn't match the equipment. Radio Shack used to have them, but not sure now.
http://www.cablewholesale.com/produ...o DB9 Female&gclid=COTZ9IydyMgCFU9ffgodFfcJOw

Secondly, get a DB9F and wire pin 2 to pin 3 to make a loopback adapter. Turn local echo off on the terminal program. If the port is working, you will see what you type on the screen with the loopback plugged in, and it'll stop when you unplug it. That confirms whether the driver and port is working.

Make sure The bits per second (baud rate), number of bits, parity, and number of stop bits match the projector. Turn OFF flow control (handshaking).


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## Mark Neisser (Oct 19, 2015)

FMEng said:


> For troubleshooting RS232, there are two things I routinely do. First, get yourself a "null modem." It's an adapter with a DB9F and DB9M. All it does is swap pins 2 and 3, but it allows a quick test to see if the cable doesn't match the equipment. Radio Shack used to have them, but not sure now.
> http://www.cablewholesale.com/products/computer-products/computer-adaptors/product-30d1-18200.php?utm_source=GoogleShopping&utm_medium=cpc&utm_term=30D1-18200&utm_campaign=Null Modem Adapter, DB9 Male to DB9 Female&gclid=COTZ9IydyMgCFU9ffgodFfcJOw
> 
> Secondly, get a DB9F and wire pin 2 to pin 3 to make a loopback adapter. Turn local echo off on the terminal program. If the port is working, you will see what you type on the screen with the loopback plugged in, and it'll stop when you unplug it. That confirms whether the driver and port is working.
> ...


Great advice. I have done all those things and even see the data looping back correctly still no joy. I ordered a couple other cables with lights and other options hopefully this will solve it. Are you controlling a projector with a Mac?


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## Chris15 (Oct 19, 2015)

Not many of us will have ever had need to control an RS232 projector from a mac.
I certainly haven't.
But RS232 is a fairly simple protocol, and the troubleshooting approach is the same whether it's a Mac, a windows box, or some other controller, like the Crestron stuff that I care about making stuff play nicely with.
I should have more time to help walk you through things later in the week.


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## ThomasL (Oct 19, 2015)

Don't have a Mac, but in my experience, the serial port is just a number, eg. 1, 2, 3...
I see a weird Port name in your attachment pic. Perhaps that is why communication to the Projector is not going through.

ThomasL


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## vman (Nov 18, 2015)

Can you tell me what Projector you are using? Maybe a Checksumm or Projector Address is missing.


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## Joshualangman (Nov 18, 2015)

[never mind; didn't realize it was you, Mark]


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## vman (Nov 19, 2015)

Are you 100% sure you have the correct command codes. I googled RS232 protocol for View Sonic projectors and found some documents. But all say

POWER ON / POWER OFF
POWER ON BE,EF,10,05,00,C6,FF,11,11,01,00,01,00
POWER OFF BE,EF,02,06,00,6D,D2,34,00,00,00,00


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