Communication by means of the PROMOTIC system drivers

It is the method that allows a data collection via the computer's serial port and via Ethernet directly to/from the PROMOTIC system by means of the PmaComm object. The MICROSYS company supplies a series of communication drivers for various standard and non-standard protocols that can be build up directly into the application by means of the PmaComm object.
The designer must configure individual messages on this approach. But the transmission is so quick (it doesn't go about the communication between two applications) and the whole communication is "fully in designer's hands" thanks to the configurability. Available drivers are also stated in the price list of the PROMOTIC system.
Drivers move data via Ethernet, over the optional serial ports COM1, COM2, ... or via the computer's serial port set in the script by the PmaComm.OpenPort method. The serial interface can be of the RS232, RS485 or RS422 type.One serial driver is using one communication interface (COM serial port), with the possibility of connecting multiple stations (dependent on protocol type). If it is necessary to connect multiple stations via different serial interfaces, then it is necessary to use more PmaComm objects.

If the designer needs a communication driver (for some special protocol), that is not listed in the PROMOTIC driver list, then there are several solution options:

Warning for serial link RS485:
This interface needs to switch the RTS signal and drivers for the Windows OS doesn't manage this easily. In the Windows OS 2000 and higher it is possible to set the switching mode (the "PmaComm > Setting the parameters of the serial link > RTS flow control" configurator - set to the state: "toggle") that allows it but there were problems in practice. That's why we recommend to use the converters to the RS485 that allow automatic switching of the RTS signal. Such tested converters are for example: