K8000 issue when configuring IO-channels as input

Kits PC Related Projects
1

Dear all,

I have an issue with my K8000 cards. I have two cards connected (one as master and one as slave) to my PC with windows XP (Dell Dimension 5000, 4CPU 2.8 GHz) with OS Windows XP (Home edition Version 2002).
I use turbo C++ to control the cards, and use the I2C-procedures and - functions in the library as supplied by Velleman.

When configuring all IO channels as outputs, everything works fine. More-over, the DAC converters work fine as well.
From this we may conclude that the parallel port communication is working properly, as well as the I2C communication between the K8000 cards and the PC.

How ever, when I configure IO-channel 1 and IO-channel-32 as input, the status of the inputs are not updated in the variables (IO or IOData), even though I see the corresponding LEDS lighting up when applying 5V to the corresponding IO-terminals.
For updating the data I use the functions ReadIOchannel(1) and ReadIOChannel(32) respectively.
Apparently, the optocouplers (4N33) are working properly as well (I have placed them in the input sockets for the corresponding channels).
When checking the configuration by the IOconfig-variable, it seems the proper channels are set as input (for which I used the function ConfigIOchannelAsInput(1) and ConfigIOchannelAsInput(32)).
I have varied the I2CbusDelay variable from 1 to 1000 and that does not influcence the result.

From above I think we can exclude malfunctioning of the communication over the parallel port (I2C), the IO-IC’s (PCF8574A), the opto-couplers (4N33).

Does anyone have an idea what might be wrong or cause this?

Thanks.
Regards,
Sven

2

Sorry, due to the age of the product, we do not have any people left with hands-on prgramming experience with this card (or a PC with a parallel port :slight_smile: )
I remember that a lot of people inverted IC24 during the assembly, as the other opto-couplers point the other way. Please check this.

3

Thanks for your quick reply. I doubled checked the orientation of IC24 as well as the opto-couplers and the other IC’s. They are all mounted according to drawings and instructions. Would it be possible for you to have a look whether other people encountered this issue in the past? Thanks in advance.