Protocol : Siemens - IEC variant BAG ( Bayernwerke AG )


Parameterization :

CDE adapter :

Modulation mode :

Baud rate :

Data byte :

Stop bit :

Parity :

Time out :

Link address fields :

ASDU address fields :

switch setting  PCM

pulse-code-modulation asynchronous

100 - 57600 baud

8 bit ( variable )

1 Bit ( variable )

even / gerade ( variable )

250 msec ( variable )

1 ( variable ) with or without structure

3 ( variable ) with or without structure

Telegram structure :

Control field :

RES reserved


Primary message 

0 = message from a  secondary station (substation) 

1 = message from a primary station (master station) 


Frame count bit  - primary station

changing value for  consecutive  SEND / CONFIRM or REQUEST / RESPOND message per station.


Frame count bit valid - primary station

0 = changing function of FCB is not valid

1 = changing function of FCB is  valid


Access demand - secondary station

0 = no access demand  on transmission of data class 1

1 = access demand  on transmission of data class 1


Data flow control - secondary station

0 = more messages are accepted

1 = further messages can cause a data overflow

LIAN / SIMO-Operation mode :

In SIMO a simple simulation mode is available. If a message with set PRM-bit and a function number from 0 to 3 is received, SIMO will return automatically an acknowledgement which can be chosen freely. To activate this mode please proceed as follows:

Open the message shell in SIMO. Choose one message buffer for the acknowledgement and edit it. Then enter the command 'rtu'. A window appears in which the number of the acknowledgement buffer must be entered. Now the simulation mode is activated; to switch it off enter 'rtu' again.

z.B.:                sw 99 =>   select Telegram buffer 99  =>
                        sa     =>   edit acknowledgement      =>
                        rtu            switch on simulation

Transmission errors

*F:BCCode : The Telegram check sum in the  BCC-Byte is incorrect.
*F:Blocklength : The Stop byte  (16H) is missing or set wrongly.
*F:TelFormat : The repetition of the length- or start sign in the telegram header is incorrect. 
*F:TimeOut :    Within a telegram there may be no pause between characters. The sensivity can be parameterized in the program LIAN.
*F:SYNC :   The receive routine initially searches for 68H, 10H or E5H. Every other character is given an asterisk '*' in SIMO and a synchronization error is noted against it in the protocol.
*F:Overflow : Error message by UART.
*F:Parity : Error message by UART.
*F:Start /Stop : Error message by UART.


MAYR Software

Wuerzburger Ring 39,  D 91056 Erlangen


LIAN DOS Protocol Simulator and Analyzer
© Copyright 1991, 1996, 2001, 2006-2010 by Werner Mayr. All Rights reserved.