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DTM-3237B – DVB-S2X Receiver with DVB-ASI Output
User Manual
4. Device Configuration and Monitoring
4.1 Control Interfaces
The DTM-3237B can be configured and monitored via a serial control protocol on USB or I
USB interface uses a serial port emulator running at 256kBaud. It is not required to select between the
control ports, the DTM-3237B will automatically use the interface on which it detects activity.
2
The I
C address is a special parameter that can only be configured through the USB interface (e.g.
with Dtm3237BUtil). Alternatively, the defaults can be used:
• The default I
2
C address is 0x60.
The USB uses the control protocol that is described below. I
different message formatting.
4.2 Control Protocol
Commands and responses are wrapped into messages described below. The DTM-3237B accepts
uppercase and lowercase characters, but will always respond in uppercase.
4.2.1 Message Format on USB
Field
Start
ASCII character
STX (0x02)
Address
2 hex digits
Category
2 hex digits
Setting
2 hex digits
Read/Write
ASCII character
'R' or 'W'
Index
4 hex digits
Data
n hex digits / n
ASCII characters
Checksum
2 hex digits
End
ASCII character
ETX (0x03)
2
Hex digits are the ASCII characters 0...9 and A...F, concatenated to form a single hexadecimal value.
USB and LVTTL serial are point-to-point connections, so there is no address and the address field is a don't care.
3
The DTM-3237B supports a single channel only, so when index is used as a channel number, it's always 0.
4
Invert all bits and add one.
5
Format
ASCII "start of text" character
2
8-bit address
Selects a "category" of settings
Selects a setting within the selected category
'R' for read and 'W' for write
Provides an extra index parameter, e.g. to indicate the
channel number
The data written or read. The data length is variable for
each setting. In case of a write operation, the data is a
(negative) acknowledgement
This is the least significant byte of the two's complement
sum of all characters in the message, excluding the STX and
ETX characters and the checksum itself
2
C uses the same protocol, but slightly
Description
3
4
15
2
C. The
5
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