FloBoss™ S600+ Flow Computer Modbus Specification Manual
D301904X012
June 2024
12
Emerson has provided the option to make this field a 16-bit value, which simply allows
more data to be transferred in each message. This is also referred to as “extended
mode.”
Note
This functionality does not adhere to strict Gould/Modicon Modbus functionality.
Available message length modes are:
8-bit byte count
The byte count field consists of a single byte, which determines the number of data
bytes in the message. For example, with data item length 2 bytes:
Address Function
8-bit byte
count Data Checksum
01 03 02 00 01 xx
8-bit item count
The item count field consists of a single byte, which determines the number of data
items in the message. For example, with data item length 2 bytes:
Address Function
8-bit item
count Data Checksum
01 03 02 00 01 00 02 xx
16-bit byte count
The byte count field consists of two bytes, which determine the number of data
bytes in the message. For example, with data item length 2 bytes:
Address Function
16-bit byte
count
Data Checksum
01 03 01 00 00 01 00 02 … up to 256 bytes xx
16-bit item count
The item count field consists of two bytes, which determine the number of data
items in the message. For example, with data item length 2 bytes: