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Discussion - Software / Access to 1 FT245B with 2 different programs simultaneously
« on: November 21, 2023, 06:57:31 PM »
Hello FTDI Community
Originally I had a DLL written in Visual Studio 6 ( win98 ) to communicate with an ISA card.
Several programs written in Visual Basic 6 can access this DLL and communicate simultaneously with the card. The DLL is written using mutex principles.
I replaced the bus part of the card with an Ftdi FT245. I rewrote the DLL to use D2xx driver. I can make the programs work, but only one at a time. I use the FT_Open, FT_Write, FT_Read, FT_Close functions.
I tried to share the handle in shared memory.
The other programs recover it well and do not open the port if it is already open, and uses the handle retrieved from shared memory to control the FT_Write, FT_Read functions, but these write and read functions return an error.
Thank you for your help
Originally I had a DLL written in Visual Studio 6 ( win98 ) to communicate with an ISA card.
Several programs written in Visual Basic 6 can access this DLL and communicate simultaneously with the card. The DLL is written using mutex principles.
I replaced the bus part of the card with an Ftdi FT245. I rewrote the DLL to use D2xx driver. I can make the programs work, but only one at a time. I use the FT_Open, FT_Write, FT_Read, FT_Close functions.
I tried to share the handle in shared memory.
The other programs recover it well and do not open the port if it is already open, and uses the handle retrieved from shared memory to control the FT_Write, FT_Read functions, but these write and read functions return an error.
Thank you for your help