AD-KEB 20 GX

The AD-KEB 20 GX contains a RS485 bus interface on which the Modbus RTU protocol is used. All control functions of the device can be executed via this bus interface. The preset standard data format is 19200,e,8,1. Adaptation to a different data format is possible at any time. The bus address (1...99) is set to the side-mounted rotary switches. The address 0 is not permitted for the bus operation. However, on this zero position the device is accessible only via the standard data format (19200, e, 8.1). The position 0 thus represents a service position, the example can be used during parameterization error.

The AD-KEB 20 GX supports two Modbus functions. These are the functions "Read Holding Registers" (0x03) and "Write Holding Registers" (0x10). With the "Read Holding Registers" function data can be read from the device and written with "Write Holding Registers" data. The individual register width is 16 bits. Please see the Modbus specification for detailed explanations of the Modbus communication. This is online available for free and can be downloaded from the Adamczewski homepage.

The following Modbus data are accessible via the RS485 bus:

Start address	Reg. number	Name	Datatype	[Code] = Value	read	write
40501	1	Address switch	U16	1...99...247	yes	yes
40502	1	Flashing function	U16	0/1...255	yes	yes
40503	1	24V Input 1	U16	0/1	yes	no
40504	1	24V Input 2	U16	0/1	yes	no
40505	1	Input contact 1	U16	0/1	yes	no
40506	1	Input contact 2	U16	0/1	yes	no
40551	2	Input frequency 1	FLOAT	0,00...2200 Hz	yes	no
40553	2	Input frequency 2	FLOAT	0,00...2200 Hz	yes	no
42903	1	Input signal type 1	U16	[0]=aktiv; [1]=Contact	yes	yes
42904	1	Input signal type 2	U16	[0]=aktiv; [1]=Contact	yes	yes
43001	1	Debouncing function 1	U16	0/1	yes	yes
43002	1	Debouncing function 2	U16	0/1	yes	yes
47209	2	Absolutely counter 1	U32	0...4294967295	yes	yes
47211	2	Absolutely counter 2	U32	0...4294967295	yes	yes
47213	2	Currently counter 1	U32	0...4294967295	yes	no
47215	2	Currently counter 2	U32	0...4294967295	yes	no
42901	1	Baud rate	U16	Index, see list below	yes	yes
42902	1	Parity	U16	[0]=even; [1]=odd; [2]=no	yes	yes
42905	1	Modbus master	U16	0/1	yes	yes
43003	1	Modbus master idle time	U16	1...36 ms	yes	yes
49102	1	Device reset	U16	0	no	yes
49105	6	Device type	String	KEB20GX	yes	no
49119	1	Firmware version	U16	MSB/LSB	yes	no

Coding baudrate list

index	0	1	2	3	4	5	6	7	8	9
baud	2400	4800	9600	14400	19200	28800	38400	57600	76800	115200

After changing the interface parameters, a device reset is required.

Modbus master mode
The device can even work in Modbus master mode to transfer data between any devices within an RS485 line.
For Modbus master operation, starting with Modbus register 40611, there are 48 consecutive data transfer sets,
with 5 configuration registers each.
Possible data type conversion (Target register count):
18 = INT to FLOAT
33 = FLOAT to INT

Start address	Reg. number	Name	Datatype	[Code] = Value	read	write
40611	1	Source address [1]	U16	1...99	yes	yes
40612	1	Source register [1]	U16	nnnnn	yes	yes
40613	1	Target address [1]	U16	1...98	yes	yes
40614	1	Target register [1]	U16	nnnnn	yes	yes
40615	1	Register count [1]	U16	1/2/18/33	yes	yes
40846	1	Source address [48]	U16	1...99	yes	yes
40847	1	Source register [48]	U16	nnnnn	yes	yes
40848	1	Target address [48]	U16	1...98	yes	yes
40849	1	Target register [48]	U16	nnnnn	yes	yes
40850	1	Register count [48]	U16	1/2/18/33	yes	yes

For the Modbus master mode, the parameter "Modbus master" must be activated and the address switch set to position 99.
Data transfer begins six seconds after activation or device restart.
A flashing green LED indicates a communication error.