VEGA INSYS Modem GPRS 5.0 User Manual

Page 92

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GPRS General

INSYS GPRS 5.0 serial

92

8.8.1.2 Data logger user data

A data logger message has the following setup:
Device ID

4 byte

2 x 8 bit for the digital inputs

2 byte

4 x 16 bit for the analogue inputs

8 byte

Checksum

1 byte

Total

15 byte

8.8.1.3 User data acknowledge of the control center

As an option, the data logger/control center software can be configured so that
for a data logger message an acknowledging message of the control center (user
data acknowledge) is sent.

Set-up:
Command (e.g. ACK)

1 byte

Checksum

1 byte

Total

2 byte

8.8.2 General data amount

For GPRS, such as for all IP-based transmission methods, the user data of the ap-
plication are packed into a TCP/IP message and sent to the remote terminal
(PUSH); the TCP/IP stack of the remote terminal (e.g. Windows) must acknowledge
each received TCP/IP message.
With GPRS, all data accumulated by the user from the IP level (incoming and out-
going) are calculated.

8.8.2.1 Transmission of user data without user data acknowledge of the remote termi-

nal

Application

/

GPRS modem

control center

Data: 15

TCP/IP PUSH: 40

Data: 0

TCP/IP ACK

: 40

Total: 95 byte

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