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Appendix d. communication example – DekTec DTM-3237 DVB-S2 Receiver User Manual

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DTM-3237 – OEM DVB-S2 Receiver with DVB-ASI Output

User Manual

35

Appendix D. Communication Example

In the examples below, grey areas in the timing diagrams are sent by the DTM-3237, while white
areas are sent by the master. The I

2

C address of the DTM-3237 in these examples is 0x60.

Serial write command on LVTTL serial control port interface or USB interface

Figure 5 shows the write command of the LNB enable at the tuner and demodulator settings (category

90, setting 9, index 0). All values are displayed as ASCII characters.

Figure 5: Write LNB enable in the tuner and demodulator settings

The command consists of the following parts:

Start character ‘STX’

Two hexadecimal address characters (“60”) (address doesn’t care, see §4.2.1)

Two hexadecimal category characters (“90”)

Two hexadecimal setting characters (“09”)

A write character ‘W’

Four hexadecimal index characters (“0000”)

Two hexadecimal data characters (“01”)

Two hexadecimal checksum characters (“50”, See Table 1)

Stop character ‘ETX’

Table 1: Checksum computation

Characters

ASCII value

6

0x36

0

0x30

9

0x39

0

0x30

0

0x30

9

0x39

W

0x57

0

0x30

0

0x30

0

0x30

0

0x30

0

0x30

1

0x31

Sum:

0x2B0

Checksum:

0x50

Serial read command on LVTTL serial control port interface or USB interface

Figure 6 shows the read command of the device type number (category 1, setting 5). The returned

data consists of 4 bytes (int32). All values are displayed as ASCII characters.