Endress+Hauser Proline Prosonic Flow 91 Operating Instructions Manual page 37

Proline Prosonic Flow 91
Command No.
HART command / Access type
50 Read assignment of the device
variables to the four process
variables
Access = Read
53 Write device variable unit
Access = Write
59 Set number of preambles in
message responses
Access = Write
Endress+Hauser
Command data
(numeric data in decimal form)
none
This command sets the unit of the given device
variables. Only those units which suit the device
variable are transferred:
– Byte 0: device variable code
– Byte 1: HART unit code
Code of the supported device variables:
See data → ä 32
!
Note!
• If the written unit is not the correct one for the
device variable, the device will continue with the
last valid unit.
• A change of the unit of the primary process variable
has a direct impact on the system units.
This parameter sets the number of preambles which
are inserted in the message responses:
Byte 0: number of preambles (2 to 20)
Response data
(numeric data in decimal form)
Display of the current variable assignment of the
process variables:
– Byte 0: device variable code for the primary process
variable
– Byte 1: device variable code for the second process
variable
– Byte 2: device variable code for the third process
variable
– Byte 3: device variable code for the fourth
process variable
Factory setting:
• Primary process variable: code 30 for volume flow
• Secondary process variable: code 250 for totalizer
• Third process variable: code 40 for sound velocity
• Fourth process variable: code 49 for flow velocity
The current unit of the device variables is displayed in
the device as a response:
– Byte 0: device variable code
– Byte 1: HART unit code
!
Note!
Manufacturer-specific units are represented using the
HART unit code "240".
As a response, the current number of the preambles is
displayed in the response message:
Byte 0: number of preambles
Operation
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