FiveCo FMod-TCP BOX User Manual page 15

Write register(s) command:
Byte#
0x00 Write (0x0022)
0x02 TransactionID
0x04 Number of bytes in
command
0x06 Register Addresses
0x07 Register value
The two previous entries are replicated for every register that has been asked for reading
... Checksum
The max length of this sequence is 180 bytes.
The module answers with the following sequence:
Byte#
0x00 Write Answer (0x0024)
0x02 TransactionID (same as
demand)
0x04 0x0000
0x06 Checksum
I2C feature
The Inter-IC bus, commonly known as the I²C bus, is a control bus that
provides the communications link between integrated circuits in a system.
Developed by Philips in the early 1980's, this simple two-wire bus has
become the de facto worldwide standard for system control, finding its way
into everything from temperature sensors and voltage level translators to
EEPROMs, general-purpose I/O, A/D and D/A converters, CODECs, and
microprocessors of all kinds.
You can find the I2C's specifications on the Philips web site at the following
link: http://www.semiconductors.philips.com/
The I2C protocol can access a device by three different manners:
Write (Start, AddW, Byte1, Byte2, ..., Stop)
St AddW
Read (Start, AddR, Byte1, Byte2, ..., Stop)
St AddR
Read After Write (Start, AddW, ByteW1, ByteW2, ..., ReStart,
AddR, ByteR1, ByteR2, ...Stop)
St AddW
A Bytes to W A Sp
A Bytes to R nA Sp
A Bytes to W R A
Number of bits
16 bits
16 bits
16 bits
8 bits
8 — 64 bits
16 bits
Number of bits
16 bits
16 bits
16 bits
16 bits
AddR A Bytes to R nA Sp
FMod-TCP User Manual v.2.8
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Example
0x0022
0x1B34
0x0003
0x02
0x1234
0x...
Example
0x0024
0x1B34
0x0000
0x...