Control 16 channel CCTV Mux using Quickstart board & RS-232
kochevnik
Posts: 30
I have a QuickStart (QS) board which I have sent and received lots of different serial data to and from a PC which appears to be working fine. On the PC end I am using a Powerbuilder program (very similar to the old Visual Basic). I basically open the com port and send signals to the QS and it echos them back - I have a hearbeat set up on the PC/Powerbuilder side to send a "?" every 1 second and the QS then replies with a 10 char string that includes the ID (just a letter between A & Z) like "QStartID-A".
All of this is working fine. Now what I want to do is have the PC send a command to the QS and then the QS will pass the command on to the Mux. The Mux is a Honeywell GV-CMP163 which were pulled out of old Walmart stores. I have the manual (see attached) and on page 39 it shows which wires are for sending and receiving RS-232 signals - but for me this is a bit confusing because page 39 of the manual shows :
9 RS-232 RX Input
10 RS-232 TX Input
11 RS-232 RX Output
12 RS-232 TX Output
To me it seems like there should be just an RX pin & and TX pin - I dont why there are 4 pins here. Also from my reading this box is not supposed to be sending any signals back to the QS board - it is just supposed to be capable of receiving RS-232 signals only.
I have pin 21 on the QS wired as a transmit line to the Mux and I am sending a signal (command "/MU" down it at 1200 baud (which is supposed to to be the default rate). I have the QS SPIN code (also attached) echoing the command I want passed on to the Mux. This is working. I just dont know how to wire up to the pins on the Mux from the QS ? I am asssuming there has to be a circuit here - out & back. Also note I can press the Menu button on the Mux and I get the menu on the screen just fine. This is the same behavior I should see once I send a "/MU" ascii string via RS-232. Now I get nothing on the screen when I send the signal. I tried sending a signal on pin 9 and on pin 10.
If it makes a diff - I have two different versions of FullDuplexSerial running on diff cogs as one is used to communicate with the PC while the other goes to the Mux.
I would greatly appreciate any advice / help etc.
SPIN Code attached
Mux Manual attached
Thx
Matt
All of this is working fine. Now what I want to do is have the PC send a command to the QS and then the QS will pass the command on to the Mux. The Mux is a Honeywell GV-CMP163 which were pulled out of old Walmart stores. I have the manual (see attached) and on page 39 it shows which wires are for sending and receiving RS-232 signals - but for me this is a bit confusing because page 39 of the manual shows :
9 RS-232 RX Input
10 RS-232 TX Input
11 RS-232 RX Output
12 RS-232 TX Output
To me it seems like there should be just an RX pin & and TX pin - I dont why there are 4 pins here. Also from my reading this box is not supposed to be sending any signals back to the QS board - it is just supposed to be capable of receiving RS-232 signals only.
I have pin 21 on the QS wired as a transmit line to the Mux and I am sending a signal (command "/MU" down it at 1200 baud (which is supposed to to be the default rate). I have the QS SPIN code (also attached) echoing the command I want passed on to the Mux. This is working. I just dont know how to wire up to the pins on the Mux from the QS ? I am asssuming there has to be a circuit here - out & back. Also note I can press the Menu button on the Mux and I get the menu on the screen just fine. This is the same behavior I should see once I send a "/MU" ascii string via RS-232. Now I get nothing on the screen when I send the signal. I tried sending a signal on pin 9 and on pin 10.
If it makes a diff - I have two different versions of FullDuplexSerial running on diff cogs as one is used to communicate with the PC while the other goes to the Mux.
I would greatly appreciate any advice / help etc.
SPIN Code attached
Mux Manual attached
Thx
Matt
Comments
For the RS232, you think it could be inverted?
I'll try that and see what happens.
edit : no luck - tried different combos of pins swapping them back and forth.
The reason why you have RS232 IN and OUT is just so you can daisy-chain them.
I am certain that you will need to use Pins 9 and 10 for communicating with the QS board.
You will also need to interface to the QS board through a level shifter such as the MAX3232
Coley
Is it because the serial signals coming off the QS using fullduplexserial must be deficient in some way ?
Thx
edit : I got the mux control working by using the serial port on my PC (actually just the Tx and Gnd pins off the serial port) -and it works great !
That's because your PC will have a level shifter fitted on the motherboard ;-)
Basically the RS232 specification calls for signal levels between +3 and +15 Volts (dependent of course upon the level shifter used).
Here is an explanation on Wikipedia http://en.wikipedia.org/wiki/RS-232#Voltage_levels
In my experience this is more likely to be from around +6 to +15V which is nowhere near the +3.3 Volts the Propeller can muster.
I am certain if you use a MAX3232 you will have some success, I use these all the time to connect the Propeller to DVR's and other Security products and they work every time.
Good luck!
Coley
In any case for now, I think I am just going to use my PC to do this, when I have more time I will experiment with the level shifter. Only got a hundred things on my todo list right now anyways
I'll mark this one as solved - I got it to work just fine from the PC and the voltage levels would definitely stop it from working from the QS