I have an instrument card which is insert to a adapter and the adapter communicate with PC via USB, but the logic way of the contact is RS232, the designer use a COM to USB chip on adapter to implement the solution. At PC side, I need to assign a COMx port in delivered software to a instrument slot, e.x, slot0<->COM4, so at both sides it seems a RS232 port, the physical link is USB. it seems that an adapter is a slot, if use several adapters and everyone connected to an individual card, I must assign to every card a COMx in delivered software and every slot is fixed slot0, such as,
card1: slot0<->COM4
card2: slot0<->COM5
card3: slot0<->COM6
card4: slot0<->COM7
every slot0 is individual and independent others.
the physical path:
card1>>adapter1>>USB cable1>>pc usb port1
card2>>adapter2>>USB cable2>>pc usb port2
card3>>adapter3>>USB cable3>>pc usb port3
card4>>adapter4>>USB cable4>>pc usb port4
So vendor provided a software called"Server Control" to manage resource, if the server control is running, the indicator LED on adapter board is highlight , then I can find the resource using VISA. If I stop the server, VISA can not find these resources.
There are several applications to operate the card which is delivered by vendor, I guess application get data from "Server" or "software module" using VISA, the manual told the application demand NI VISA runtime.
Under the application folder, I found some 16bit DOS software called "software module" , document told these DOS module manage the data flow between PC and instr.
I am not familiar with such a architecture but I need to program my own software to operate the instrument.
Attachment is the organization of the system provided by supplier's doc.
Maybe my knowledge is not enough to understand such a system,
Thanks for your sincerely reply.
Rexxar
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*The best Chinese farmer*
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