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Basic parameters and properties, Introduction, 9 basic parameters and properties – Bronkhorst EL-FLOW Prestige User Manual

Page 27: 1 introduction

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Bronkhorst High-Tech B.V.

EL-FLOW Prestige

27

9.17.084

3.9

Basic parameters and properties

3.9.1

Introduction

Most instrument parameters can only be accessed with digital communication. For each communication protocol the instrument

parameters are accessed differently. When using Bronkhorst software programs FlowView or FlowPlot, easy access is provided to

the mostly used parameters by menu interfaces. When using other communication methods the addressing method for the

supported communication protocol is presented for a number of basic parameters in a table as shown below:

Type

Access

Range

FlowDDE

FLOW-BUS

Modbus

[type]

RW

[x]…[y]

[DDE par]

[Pro]/[Par]

[address]/[index]

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

The parameter is read-only

RW

The parameter can be read and written

RW

The parameter is protected and can only be written when the ‘Init Reset’ parameter is set to 64.

See section 4.2.2 for more details.

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. Refer to section 3.4.2 for more information about FlowDDE.

Within this manual, a reference to a parameter name is denoted by writing the DDE parameter number in front of

the parameter name, e.g ‘

8

Measured Value’. See section 3.9.6 for a parameter list, sorted by DDE parameter

number.

FLOW-BUS

Within the FLOW-BUS protocol (Propar when using RS232) parameters are divided into a ‘Process’ and

a ‘Parameter’ number. To address parameters using the FLOW-BUS/Propar protocol write both numbers:

[Pro]

Process number

[Par]

Parameter number

i

www

See document 9.17.027: ‘RS232 interface with FLOW-BUS for digital instruments’ for detailed information. http://

www.bronkhorst.com/files/downloads/manuals_english/917027manual_rs232_interface.pdf

Modbus

Parameters can be read or written via the Modbus protocol by specifying either the PDU Address or the register number. The PDU

Address is a hexadecimal number (identifiable by the ‘0x’ prefix), which corresponds to the decimal register number minus one, e.g.

PDU Address 0x0000 equals register number 1, PDU Address 0x000A equals register number 11 etc.):

[address] Hexadecimal PDU Address

[index]

Decimal register number

For the Modbus protocol every two bytes are addressed separately.

PROFIBUS DP, DeviceNet

TM

, EtherCAT® or PROFINET

Refer to the specific field bus manual for reading/changing parameters via field bus communication.