Equipments (Devices) > SSW900

Only the variables created in the GLOBAL group of the variables table, called Global Volatile Markers, and that have a user-specified address, will be accessible by modbus protocol, when their are within the following range:

TYPE

Address Range

Modbus Map

Description

%MB: BOOL

0 - 7343

40000 - 49999
(Coil)

Each modbus address represents 1 bit of the address content.
After address 1250, the bit is not accessible via modbus.

%MB: BYTE, SINT, USINT

%MW: WORD, INT, DINT

%MD: DWORD, DINT, UDINT, REAL

8000 - 11671
(Register)

Each modbus address represents 2 bytes of the address content.
After address 7344, the data is not accessible via modbus.

Modbus functions with access to volatile global markers with address defined:

1.	Read - Modbus Function 01 "Read Coils"

2.	Read - Modbus Function 03 "Read Holding Registers"

3.	Write - Modbus Function 05 "Write Single Coil"

4.	Write - Modbus Function 06 "Write Single Register"

5.	Write - Modbus Function 15 "Write Multiple Coils"

6.	Write - Modbus Function 16 "Write Multiple Registers"

Example of volatile global markers declaration with address defined in variables table of the ladder editor:

wpshelp_variables_table_global

wpshelp_variables_table_global2