Connection To The Computer; Bit Rate; Data Structure - JUMO CEROS S01 M Interface Description

2.2.4

Connection to the computer

NOTE!
The digital pressure measuring cell can be connected with a PC/Notebook via PC-Interface with Con-
verter USB/I²C TO39.
 see chapter 4.3 "Connection to the computer", Page 19
2.3

Bit rate

The digital pressure measuring cell works over two sets of bitrates (transfer speed). The maximum clock
frequency is 400 kbit/s. Furthermore the maximum bit rate depends on the cable length and the pull-up
resistors. So it is recommended to start with lower bit rates and test the maximum possible bit rate by
increasing it.
Mode
Standard mode (Sm)
Fast mode (Fm)
2.4

Data structure

SCL
SDA
• Idle period
During inactivity of the bus, SDA and SCL are pulled-up to the supply voltage VDDA.
• Start condition
Every data frame starts with a start condition. A high-to-low transition on SDA while SCL is at the high
level indicates a start condition. Every command must be initiated by a start condition sent by a master.
Max. bit rate
100 kbit/s
400 kbit/s
start valid data
condition
2 I²C - communication
proper
change
of data
Direction
bidirectional
bidirectional
stop
condition
9