Bronkhorst®
Instruction Manual MI Series Industrial mini CORI-FLOW™
9.17.120A
29
4
Digital parameters
Each instrument is controlled internally by a number of digital parameters, most of which can only be accessed using digital
communication. Each communication protocol uses its own methods for communicating with instruments and accessing
parameters.
This section describes the most commonly used parameters for digital operation of the mini CORI-FLOW™. Descriptions are
grouped by category in tables as shown below:
Type
Access
Range
FlowDDE
FLOW-BUS
Modbus
[type]
RW
[x]…[y]
[DDE par]
[Pro]/[Par]
[address]/[register]
In this manual, parameter names are printed in italics (reverted to
normal
where embedded in italics, like in this tip).
Type
Unsigned char
1 byte unsigned integer (0…255)
Unsigned int
2 byte unsigned integer, MSB first (0…65535)
Unsigned long
4 byte unsigned integer, MSB first (0…4294967295)
Float
4 byte floating point, IEEE 32-bit single precision, MSB first
Unsigned char [x] x byte array (text string)
Access
R
Parameter value can be read
W
Parameter value can be written
Parameter is secured and only accepts values if parameter
Init Reset
is set to 'unlocked' first
Range
Some parameters only accept values within a certain range:
[x]
Minimum value of the range
[y]
Maximum value of the range
FlowDDE
Parameter number within FlowDDE
FLOW-BUS
Within the FLOW-BUS protocol (ProPar when using RS232), parameters are identified by a unique combination of a process
number and a parameter number:
[Pro]
Process number
[Par]
Parameter number
Consult the
RS232 manual
(document no. 9.17.027) for detailed information.
Modbus
In the Modbus protocol, parameters are accessed by specifying their unique decimal register number or corresponding PDU
address (Protocol Data Unit). The PDU address is the hexadecimal translation of the register number minus 1, e.g. register
number 1 corresponds to PDU address 0x0000, register number 11 corresponds to PDU address 0x000A:
[address]
Hexadecimal PDU address
[register]
Decimal register number
Modbus address blocks are two bytes big. Larger data types use up to 8 subsequent address blocks, resulting in a
maximum variable length of 16 bytes. Values longer than the maximum length are truncated.
Other interface protocols
Consult the specific fieldbus manual for accessing parameters using fieldbus communication (see
).