3 special hints for devicenet and ethernet-ip, Special hints for devicenet and ethernet-ip, Fieldbus interface – Rice Lake PR5220 Ethernet Transmitter User Manual

Page 140: Pr 5220 instrument manual

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Fieldbus Interface

PR 5220 Instrument Manual

EN-140

Sartorius

Example: Reading the Gross Weight
The master writes value 8 in

Read_Value_Select

(byte 4)

of the input area.

Input area

Byte Value

Description

0

1

2

3

4

8

Gross

5

6

7

The master waits, until value 8 was reflected in

Read_Value_Selected (byte 4)

of the output area.

Output Area

Byte Value

Description

0

00

Gross value

1

00

"

2

4

"

3

D2

"

4

8

Gross weight
request was
detected

5

Status

6

Test
active

Command status

7

Stand-
still

Inside
ZSR

Center
zero

Below
zero

Over-
load

Above
Max

Adc
error

Device status

Bit 7

Bit 6

Bit 5

Bit 4

Bit 3

Bit 2

Bit 1

Bit 0

The gross value (hex:000004D2 <=> 1234) can be read from bytes 0...3. When the

'Overload', 'Test Active' or

'ADC error' bits are set, the read value is invalid.
Negative values are output in two’s complement.

7.3

Special hints for DeviceNet and EtherNet-IP

With these field bus types, the sequence of the bytes (only applicable for words and individual bytes) is
inverted.
With long words, this problem does not arise due to compensation by the firmware.
Sequence of bytes 0…3, e.g. with device type and software version, see table:

Standard sequence

Sequence for DeviceNet and EtherNet –IP

Byte 0

TYPE MSB

Byte 0

SUBVERSION

Byte 1

TYPE LSB

Byte 1

MAINVERSION

Byte 2

MAINVERSION

Byte 2

TYPE LSB

Byte 3

SUBVERSION

Byte 3

TYPE MSB

Consequently, the sequence on the PLC side must be changed when using the DeviceNet and EtherNet –IP field
bus types.

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