RS232 interface to mass flow controller

[garyca]

Has anyone any info on connecting a PC to the serial interface of a Brooks 154 microprocessor controlled readout unit for Brooks mass flow controllers?

Thanks

 

[m777182]

Using serial interface on PC is tricky: you could write your own code to operate com1 or com2 or you have to get a driver; there are many on the market. Drivers alows you to set the communication parameters on your PC side to those on the flowmeter side.I do not know the Brooks 154 but it cannot be much different from the general RS232 equipment.In any case you need a detailed description of the communication protocol and wiring.
In many cases you can set communication parameters on the data sending side to some extent.
Mostly you can set the transfer rate(Baud rate),format of the transfered information(word lenght, control of parity) and the way of transfer control: sometimes a system uses hardware control, where by separate wires both sides exchange signals to each other that data are ready,that transmission may start etc. In other cases there are only three lines for transmission: common ground, a line to send data and a line to transmit data. A transmission starts by sending a specific character and at the end of the transmission another specific character is sent.
In some cases the measurement equipment has its own clock that controls time intervals among data packages; more often the PC sends a requirement to the terminal equipment to send data.
In a simple version the data are transmited in an ASCI format with a fixed lenght(e.g 20 bytes); it is however possible to change the data into a binary format. In some cases the first piece of the data contains an information about the lenght of the data record that will be transfered.If you are a novice on this field you will need a few months to be able to write your own code, in Excel maybe even more.
m777182