FSBUS MAX232 Types

[Roel_Wessels 0]

Ok I've tried all your advices, and some seem to work. As I've said I've now two FSCOM cards which behave equally wrong. I desperatly want them to work! (Or at least one of them ;-) )I still think the cable can be the problem. I've adjusted it as can be seen on the picture below. I used the licorice cable and interconnected the cables in the center to make it sure it's ok.http://bev02.adsl.utwente.nl/VliegVrienden...SerialCable.jpgI am beginning to think that the connection scheme I use may be wrong or outdated ? Can anyone comment on this? This is the one I made based on the one below that.http://bev02.adsl.utwente.nl/VliegVrienden...inoutScheme.gifOriginal version from FSBUS docshttp://bev02.adsl.utwente.nl/VliegVrienden...IISchematic.jpgRoel

[Guest Erups]

One is nailed:connection from serial port pin 8 goes to pin 8, should instead go to pin 9.Check on the schematic: pin 7 of the MAX232 should be connected to pin 8 of the serial port.In your case it is left unconnected.I can't see any other errors in the serial port connection cable.Hope this can solve your problem!

[Roel_Wessels 0]

Yikes! Claudio, you were right.However, it seems that I made an error drawing the diagram. Because the flat cable unfortunatly has the right connection. I'm very sorry.The thing with the diagram is that I checked and rechecked and still things slip trough. I hate that!Like I said I've made progress because the boards now give out the correct voltages. But the PIC won't flash...I'm almost beginning to feel ashamed asking so many questions. Again, thank you guys so much for your help until now!Now, to get an progress on my FSBus System:What would you do, being in this situation?What are the area's I should look at to get the troubles I have solved? What is most probable?Roel.

[Guest Erups]

You could try this:disconnect the fscomm from everything, take out the max232, with your tester in "continuity" mode, verify pins 10,11,12 on the max232 socket.Do this:put one lead of the tester in one of the pins of the max232 socket, then use the other to prob for eventual shorts between the differents pins on the FSBUS connectors.Each max232 pin should result continous to only its own signal.Then apply nominal power to the fscomm3 and try applying 12V dc to pins 7 and 4 of the serial port connector, and check that corresponding pins on the FSBUS connectors change from 5V to zero.This should ensure that everything is ok.If that's the case, and your serial cable is ok...I don't know what else to do :(There MUST be something screwed to track down...

[Roel_Wessels 0]

Ok Claudio will try that and report back..Roel.

[Roel_Wessels 0]

BTW,Pin 10,11,12 what counting do you use?like this16 15 14 13 12 11 10 91 2 3 4 5 6 7 8(which it should be, I think)or did you use9 10 11 12 13 14 15 161 2 3 4 5 6 7 8(which makes more sense in your problem solving scenario)rgds,Roel.

[Roel_Wessels 0]

Ok with the help of Claudio I tried the following:Claudio's Big Troubleshooting Guide:>You could try this:>disconnect the fscomm from everything, take out the max232,>with your tester in "continuity" mode, verify pins 10,11,12 on>the max232 socket.First of all I used these pins:http://bev02.adsl.utwente.nl/VliegVrienden...noutScheme2.gifPin 10 - Is okay: i.e. only one line is continuous, the rest isn'tPin 11 - Is okayPin 12 - Is okay BUT gives 1500kOhm on the GND pin (I think mainly caused by the N4148 diode at the bottom of the board connecting it. This seems to be ok? When I reinserted the MAX232 and applied 12V to the power the board, the continuity between the pins was 0Ohm... (still ok?)>Then apply nominal power to the fscomm3 and try applying 12V>dc to pins 7 and 4 of the serial port connector, and check>that corresponding pins on the FSBUS connectors change from 5V>to zero.Here's what I did:-Power up the board using 12V-Reset the board using jumper-Jumper on pins to activate program mode-->Pin 1 and 2 to the FSBUS connectors are now both measured at 5V-Applied 12V to:-->Pin 4 of serialport connector: Pin 1 is 0V and Pin 2 is 5V (on FSBUS connectors)-->Pin 7 of serialport connector: Pin 1 is 5V and Pin2 is 0V (on FSBUS connector)Which seems ok.>This should ensure that everything is ok.>If that's the case, and your serial cable is ok...>I don't know what else to do :(>There MUST be something screwed to track down...Yeah there must be. :-mad And I'm gonna find out eventually :-madRoel.

[Guest Erups]

>BTW,>>Pin 10,11,12 >>what counting do you use?>>like this>>>16 15 14 13 12 11 10 9>1 2 3 4 5 6 7 8>(which it should be, I think)Looking at any chip with the serigraphy readable, and pins aligned horizontally, prcatically ALL chips have pin numbered in ccw starting from lower left.That's like you reported above.What you wrote below, and how you did the test is no use as you where testing other things.

[Guest Erups]

>First of all I used these pins:As i said above these are wrong:these are pins 13,14,15>Pin 12 - Is okay BUT gives 1500kOhm on the GND pin (I think>mainly caused by the N4148 diode at the bottom of the board>connecting it. This seems to be ok? When I reinserted the>MAX232 and applied 12V to the power the board, the continuity>between the pins was 0Ohm... (still ok?)It may well be.You are measuring pin13 which is the pin that commands the MCLR trasnsistor to give the 13,5v.It may well be that you pass through the junction of the transistor, thus reading conduction.>Here's what I did:>-Power up the board using 12V>-Reset the board using jumper>-Jumper on pins to activate program mode>>-->Pin 1 and 2 to the FSBUS connectors are now both measured>at 5V>>-Applied 12V to:>-->Pin 4 of serialport connector: Pin 1 is 0V and Pin 2 is 5V>(on FSBUS connectors)>-->Pin 7 of serialport connector: Pin 1 is 5V and Pin2 is 0V>(on FSBUS connector)>>Which seems ok.And in fact is.Hmmm...This is foundamental: if this works i dunno what else could not work.Have you tried another max232?Have you tried everything on another compupter?Try also measuring the output of the serial port, while changeing the troubleshooting in the software.When you see in the software 0V for data and/or clock and/or MCLR-reset, you should read 12V on pin 7 and/or 4 and/or 3 of the serial port.When you put eighter signal to 5V/13,5V the corresponding pin on the serial port should go to -12v.

[Guest Erups]

Roel have you received my private message?

[Roel_Wessels 0]

Claudio,Not at home too. Will test when possible!Rgds,Roel.

[Roel_Wessels 0]

Claudio and others,I made a third FSCOMIII card yesterday and I get the exact same result as I got with the other two cards. It seems that the problems are replicated. I am now certainly ruling out short-circuits and line-breaks. I tested the last two cards while soldering, step by step and everything seems fine.I tested the cards on two different computers. The voltage behaviour I get are the same as I mentioned in the posts before.I used parts from two different shops. The one component I used from one shop on all 3 cards is this one which might be the problem.It is the 100n capacitor that is used twice on the FSCOMIII board. I used this one:MKH-(MKT)Capacitor 100nFFilm CapacitorWithout shieldingTolerance 5 %100 Volt, RM 7,5 mmFilm "Poly