6. Function blocks
6.1 Manufacturer function blocks
Slave ID
The value range is 0 to 255.
If a slave ID of 0 is selected, the Modbus RTU master will send the request as a
broadcast to all configured Modbus RTU slaves. In this case, only function codes for
write jobs can be sent (FC5, FC6, FC15, FC16). The request will be sent with default set-
tings, i.e., with a big-endian byte order and an address offset of 1, i.e., with the Auto-
decrement on all addresses option disabled.
Response timeout
As soon as the slave does not respond within the specified time, function block out-
put E1 will be set to a state of 1. Whether the registers are cleared when there is a
timeout will depend on the setting configured with the option of the same name
under Project view / Cyclical data tab – please refer to → " Clear register on timeout",
page 783 as well. 3000 ms is the default value.
32 bit mode
Only available on easySoft Version 7.40 or higher.
Only available on firmware version 1.40 or higher.
Otherwise this option will not be available.
Enable this option if you want register contents that are written or read with function
codes FC3, FC4, FC16, FC23 to be interpreted as double words. This will cause two
consecutive word registers to be combined into a double word. The number of ele-
ments per request can then be exclusively in steps of two.
This option is also important when it comes to data interpretation regarding the byte
order.
1. Requirement
The parameters for the 1st request are used to define the easyE4 marker range on
which the function code will be run. The range's word markers will be either written
to the Modbus RTU slave or read from it and stored in the easyE4's word markers.
Start
address
The address of the first Modbus RTU slave element that should be written to or read. The value
range is 0 to 65535.
Keep the 0-based address system in mind.
If the address range does not match the Modbus RTU slave's address range
because the former starts from 0 and the latter from 1, you will need to use an off-
set.
In this case, you will need to set the start address to the original value minus 1.
No. of Ele-
ments
The number of elements that will be read from the slave's Modbus RTU map in the easyE4 marker
range or that will be written from the easyE4 marker range to the slave's Modbus RTU map.
Depending on the specific function code, "element" may refer to different data formats of data type
BIT or WORD.
If the 32-bit mode option is enabled, only a number of elements that can be divided by two will be
accepted.
easyE402/24 MN050009ENEaton.com
543
To Next Page
Loading...
Need help?
General