1 structure of the ethernet data telegram, Structure of the ethernet data telegram, E94aycen communication manual (ethernet) – Lenze E94AYCEN User Manual

Page 39

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EDS94AYCEN EN 9.0 - 09/2012

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39

E94AYCEN communication manual (Ethernet)

Parameter data transfer

Structure of the Ethernet data telegram

7.1

Structure of the Ethernet data telegram

The GCI protocol is used for communication.
The Ethernet data telegram is shown below. Here, the GCI header represents the part of

the program that is independent of the type of command transmitted.

[7-2]

Structure of the GCI header within the Ethernet frame

E94YCEN015

Ethernet
Header

IP Header

TCP/IP
Header

P0 … P4

Ethernet
CRC

SIZE

GTI

rsp a

GMT

GSV

res

GCI Header

SIZE

res

res

GMQ

Field

Size

Description

GMT

1 Byte

GCI message type

0x01 Reserved

GSV

1 Byte

GCI service identification

0x82 Reading parameters
0x83 Writing parameters

GMQ

1 Byte

GCI message qualifier

rsp Request/response (1 bit)

0: request

1: response

a Abort (1 bit)

0: data transmission ok

1: data transmission aborted

res Reserved (6 bits)

Data contents = 0

GTI

1 Byte

GCI transaction ID

0x00 Serial number (transaction identification)

• For each client a definite serial number (0 ... 255) is allocated.

• The serial number in the multitasking environment is used for

referencing to the calling tasks (reverse transaction).

...

0xFF

SIZE

2 bytes

User data length (P0, P1, P2, P3, P4)

0x14 20 bytes

... ...

0x114 276 bytes

res

2 bytes

Reserved

0x0000 Data contents = 0

Bit 7

rsp a

Bit 6

Bit 5 ... Bit 0

res

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