Kurz Instruments, Inc. 831-646-5911
2411 Garden Road www.kurzinstruments.com
Monterey, CA 93940
Serial Output. The most common digital communications protocol used today is
Modbus. It has been around for decades and is well supported with many third party
OPC servers that can be configured to read parameters from our flow meters that are then
used by client HMI or SCADA programs on the same computer or network like Excel,
Lookout, Wonderware, Fix32, etc. Please see the manual for more on OPC and the
Modbus register assignments for the MFT B-series product line. The 155 Flow
Computer does not have Modbus available.
To setup the digital output we need to choose the protocol, baud rate and serial port type.
A. Protocols:
1. Remote Terminal Mode is where you talk to the meter from a Laptop using Tera
Term. Both the MFT B-Series and 155 Flow Computers support this.
2. Logging a meter summary to the USB port can be generated from an internal
timer or “l” command. The data can be logged as a .csv file for direct loading
into a spreadsheet using Tera Term.
For the 155 Flow Computer this is the “x” command. With the terminal echo off,
you can then capture just the meter summaries by issuing the “l” or “x”
commands. The 155 data is best captured and converted to a spreadsheet format
using the Kurz PC data logging program.
3. Modbus, which is a multi-point protocol that can be used on the RS-485 port.
Both the Modbus ASCII or RTU protocols are supported. The device address
may be any number between 1 and 247. Modbus TCP/IP requires a serial to
Ethernet gateway as the native interface is RS-485.
B. Baud Rate:
MFT B-Series: This can be 9.6 to 57.6 k and is set from the keypad or USB
interface..
155 Flow computer: This is fixed to 9.6 k baud.
C. Serial Port Type:
155 Flow computer has an RS-232 or RS-485. It is jumper selected as there is
only one port, which can be either logic level standard. The 155Jr/A/B do not have RS-
485 built in.
MFT B-Series: USB and RS-485.
USB is convenient for talking to PCs but the RS-485 is designed for long distances and
addressing multiple devices. When using the RS-485 connection there are bus loading
resistors and other issues that are needed for reliable operation defined on the field wiring
diagrams that need to be consulted. The USB interface requires a Driver to be installed
on the PC to emulate a COM port
MFT B-Series gateway to Profibus DP, Device Net or Ethernet is available from
Kurz based on the Anybus Communicator line.
360208-D Models 155, 454FTB, 504FTB, 534FTB 20
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