For easy integration of this driver into the application it is handy to use: Preconfigurations in group "MicroUnit PLC"
Some special peripheries require another length of the data but this protocol isn't described in the technical documentation and it isn't supported by the present version of the driver.
It is the mandatory parameter of the message that defines the address of the unit (module) in the RS485 network. If the segment 2 of the DIL switch SW is switched ON, the address is fixed and it is set to 0. If the segment 2 is switched OFF, the address is given by the value on the address 62 (COM_BD) of the configuration EEPROM (periphery no.0). The address and the speed rate are always initiated only on switching on the power of the module.
It determines the function that is requested from the module and it is the communication message parameter of the PmCommMsg object. The selection of the function is made by the "FUNCTION" listbox in the message parameters window. Besides defined functions it is possible to set the "User DEFINED function" function. Then the extra "Function" data item appears on the Data-sent page into which the designer enters the function number directly, according to the technical documentation, or if needed, then according to the numbers stated before the function names in the "FUNCTION" listbox.
It determines which of functional blocks is written or read. For example digital I/O, timers, configuration EEPROM, and others (see the list) belong here. The periphery is selected by the same way as the function, by the "PERIPHERY" listbox in the message parameters window respectively. Like at functions it is possible to set the "User DEFINED periphery", which causes adding the "Periphery" item into the Data-sent page.
The protocol library supports four extra formats of transmitted and received data, the following data types respectively:
On entering these data types the type conversion to the MicroUNIT modules compatible format is kept.
Note: If you address, for example, the internal unit like the EEPROM configuration, then have a look thoroughly at the description of addressing in the documentation. You can see that some peripheries have their own way of addressing that is not described in the AIBus protocol specification (instead of 2-bytes ADR, 1-byte ADR is sent twice). That's why the data format of 4-bytes variables is implemented.
|Number of data bits||8|
The transfer is asynchronous in Full-duplex or Half-duplex mode. In case of the Half-duplex mode (for example on using RS485) it is necessary, according to the AIBus documentation, to control the parity bit (the prompt is transmitted with the even parity, the response with the odd parity). The PROMOTIC driver ignores the parity bits that's why it is possible to set to the fixed even parity.
|Number of stop bits||1|