BRONKHORST CORI-TECH B.V.
3.9 BUS / digital operation
Operation via fieldbus reduces the amount of cables to build a system of several instruments and offers more
parameter values to be monitored/changed by the user.
See instruction manual: operating digital mass flow / pressure instruments for more details (document nr.
9.17.023).
Operation by means of a fieldbus adds a lot of extra features (compared to analog operation) to the
instruments.
Such as:
- setpoint slope (ramp function on setpoint for smooth control)
- 8 selectable fluids
- direct reading at readout/control module or host computer
- testing and self diagnosis
- response alarm (setpoint-measure too high for too long time)
- several control/setpoint modes (e.g. purge/close valve)
- master/slave modes for ratio control (FLOW-BUS only)
- identification (serialnumber, modelnumber, device type, user tag)
- adjustable minimal and maximal alarm limits
- (batch) counter
- adjustable response time for controller when opening from zero
- adjustable response time for normal control
- adjustable response time for stable control (|setpoint-measure| < 2%)
Special software like FlowDDE, FlowPlot and FlowView can be used to control these settings.
For operation of digital instruments by means of a specific fieldbus system or RS232, see following
documents (available as PDF-file):
•
for FLOW-BUS document number: 9.17.024
•
for PROFIBUS-DP document number: 9.17.025
•
for DeviceNet document number: 9.17.026
•
for RS232 document number 9.17.027
•
for Modbus document number 9.17.035
Note:
Special RS232 cable has partnr. 7.03.348 and consists of a T-part with 1 male and 1 female 8DIN connector
on one instrument-side and a normal female sub-D 9 connector on the side of the computer.
By means of this cable it is possible to offer RS232 communication and still be able to connect power-supply
and analog interface through the (analog) 8DIN connector.
RS232 communication is only possible with a baudrate of 38.4 KBaud and can be used for either:
•
Uploading new firmware by means of a special program (for trained BHT-service personnel only)
•
Servicing your instrument using BHT-service programs (for trained BHT-service personnel only)
•
Operating your instrument using FLOWDDE, FLOWB32.DLL or RS232-ASCII protocol (end user)
9.17.031
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