MLT PX-10

CXPI is supported.
MLT PX-10
The MLT PX-10 logs the control results of CAN / LIN / ISO 14230 / IE Bus / I2C / CXPI
communications and port input / port output / analog input on the same time axis. The Windows
application for the MLT PX-10 displays the results in real time. The MLT PX-10 comes with a variety
of sending functions and trigger functions. Accordingly, it can be used for simulation of communication
nodes.
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What is CXPI?
CXPI is an abbreviation for “Clock Extension Peripheral Interface,” and is an in-vehicle
communication standard that has been developed by the Society of Automotive Engineers of Japan,
Inc. (JSAE). CXPI meets the in-vehicle communication requirements for input/output-related fields.
This protocol is useful for multiplexing of communication lines. CXPI is being standardized by the
International Organization for Standardization (ISO) with Japanese domestic manufacturers playing
a central role. (As of February, 2016.)
Standard number
JASO
D015
SAE
J3076
ISO
(Proposed)
(As of February, 2016.)
Features of CXPI

CXPI is on the basis of periodic sending according to the master node schedule. For CXPI, the
CSMA/CR (Carrier Sense Multiple Access with Collision Resolution) method and
multi-master configuration are adopted, by which event sending is also supported. CXPI has
the advantages of “securing high event responsiveness” and “easy node addition” with the
support of event sending.
Event Sending
Periodic Sending

The master node always sends a pulse-width modulated clock. Each sending node sends data
encoded over the clock. Each receiving node decodes it.
Master Node
Slave Node
CXPI
Transceiver
Microcomputer
1 bit
(UART)
Logical value 1
Logical value 0
2
Outline specification
BUS type (single wire)
Number of connected nodes
16 (The total extension of the communication bus is 40 m.)
Maximum baud rate
20 kbit/s
Access method
CSMA/CR (multi master)
Frame
Network topology
ID
7 bit (+ 1bit Parity)
Type
<Normal Frame>
<Long Frame>
Maximum data length
12 Byte
255 Byte
Error detection method
8 bit CRC
16 bit CRC
Data Length Code, Counter, and others.
modulation method
PWM (All slave nodes synchronize in each bit of bus clock.)
Physical interface configuration
Each node is connected by one communication line. Each node uses VBAT (+12V). Each node is
equipped with a termination resistor and open drain transceiver.
VBAT
VBAT
VBAT
Transceiver
Transceiver
Controller
Controller
Master Node
Transceiver
Controller
Slave Node
Slave Node
Access method
2 access methods are defined by CXPI. A network mounts one of access methods according to the
system requirement.

Event Trigger Method (Importance placed on event responsiveness.)
Schedule
: Timing by which a request by event
occurrence can be sent

Polling Method (Importance placed on communication periodicity.)
Schedule
Request (PTYPE)
: Timing by which a request by event
occurrence can be sent
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Frame configuration * Only a normal frame by the event trigger method is introduced.
A frame consists of a PID field and response field. The PID field is sent by the requesting node and
the response field by the responding node.
: IBS
PID
field
Frame
Info
DATA
DATA
D
DATA
: IFS
CRC
Response field

PID field
The PID field is 1-byte, consisting of a 7-bit frame ID and a 1-bit parity bit.
start
bit
bit0
bit1
bit2
bit3
bit4
bit5
bit6
Frame ID

bit7
stop
bit
Parity bit
Response field
The response field consists of frame information, data, and CRC.

Frame information
Frame information is 1-byte, consisting of a 2-bit CT indicating frame continuity, 2-bit
NM for Wakeup/Sleep processing, and DLC indicating data length.
start
bit
bit0
bit1
bit2
CT

bit3
bit4
bit5
NM
bit6
bit7
stop
bit
DLC
Data
Data is a 0 to 12-byte arbitrary value specified by DLC in frame information.
start
bit
bit0
bit1
bit2
bit3
bit4
bit5
bit6
bit7
stop
bit
Data

Cyclic redundancy check (CRC)
CRC is a 1-byte predetermined computational result for error detection processing.
start
bit
bit0
bit1
bit2
bit3
CRC
4
bit4
bit5
bit6
bit7
stop
bit
Outline of the MLT PX-10 functions (CXPI)
Components
MLT PX-10 Navigator
CXPI
Communication Bus
USB cable
MLT PX-10 Hardware
Connection example

BUS monitoring
ECU-1
(Master Node)
ECU-2
(Slave Node)

ECU-3
(Slave Node)
ECU-4
(Slave Node)
Node simulation
master node
simulation
slave node
simulation
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Decoded waveform output
!!! Use it as a monitor signal
with an oscilloscope, logic
analyzer, etc.
PIN
Name
1
+B(external power)
2
MON(CH1)
3
GND
PWM decoded waveform
4
5
GND
6
CXPI(CH1)
:
CXPI bus waveform
:
Log example
!!! Frame-by-frame display in items
is easy to see at the time of log
analysis.
[ Log of PID and response fields ]
Parity
ID
PID frame
Response frame
000000384> 10:34:20 +108.0027794 I CXPI 1 OK 0 0 16
000000385> 10:34:20 +108.0076826 O CXPI 1 OK 1 0 16 6 0 3 FF FF FF FF FF FF 86
Consecutive
numbers
Time
Relative
time Type
Protocol
Data
CRC
Frame info
Frame type
Channel Status
!!! A log indicating bus
conditions is also output.
[Log of various events ]
Wakeup
Clock
000000005> 10:33:01 +7.659449550 O CXPI 1 OK (129:ISTR=Wakeup) (132:TIME=420us)
000000008> 10:33:01 +7.668215410 I CXPI 1 OK (128:ISTR=Clock_started)
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Error type and display
!!! If a communication error
occurs, the corresponding
error code is displayed.
000000238> +12.24885320 O CXPI 1 NG 1 1 12 8 0 1 FF FF FF FF FF FF FF FF BE (0:ERR=00000002)
Error Code
Bit
Error type
Meaning of error
:
Undefined
---
transmission timeout
Lapse of a specified time in an unsent state after a
14
transmission instruction from the application.
13
abnormal reception
Entry into such a state that the clock stops in the middle of
receiving, etc.
12
abnormal transmission
Entry into such a state that the clock stops in the middle of
sending, etc.
:
Undefined
---
8
unknown frame sequence
Receiving of some data in such a state that the ID is
unrequested, etc.
7
data length error
Detection of inconsistency between DLC and data count.
6
transmission failed
Failure in sending the PID field because of bus occupation by
other node(s).
5
transmission data lost
Occurrence of an arbitration defeat in sending the PID field.
4
framing error
Detection of inversion of a logical value in start bit or stop bit.
3
counter error
Detection of abnormality in frame continuity.
2
parity error
Detection of an error in PID field.
1
CRC error
Detection of an error in response field.
0
bit error
Detection of inversion of a logical value in sent data.
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User module
You can write a user-defined program that runs on the MLT PX-10 Navigator—this is called a
Navigator user module. Navigator user modules allow sending of, response to, and display of any
frame, and easy user operation with GUI components. Navigator user modules are written in
pScript, which is our originally designed and developed script language. Because its grammar is
simple, descriptions can be made easily without programming experience.
!!! You can create a GUI
User Module Editor
on your own.
Navigator user modules can provide a
The results of editing
GUI, which can be easily edited by the
are stored as pScript
User Module Editor.
code.
program(pScript)
Navigator
user
modules
can be created by any text
editor.
Setting to the MLT PX-10
Navigator
Navigator user module
MLT PX-10 Navigator に
組み込まれる形で動作します。
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
For reprinting or reproduction, our permission is required.

The correctness of the information contained in this document has been doubly assured. However, we shall
assume no liability for any customer damage caused by imperfection of the descriptions.

The descriptions are subject to change without notice.
For sales related inquiries
Company:
PRISM Co., Ltd. Chubu Branch Office
Sales Rep:
Sugiura / Fujimoto
E-mail:
For technical related inquiries
Company:
Website:
sugiura@prism-arts.co.jp ,
E-mail:
PRISM Co., Ltd.
http://www.prism-arts.jp/
info@prism-arts.jp
fujimoto@prism-arts.co.jp
Address:
1-11-15, Sasame-cho, Anjo-shi, Aichi
Address:
446-0073, Japan
1-10-17, Konan-cho, Fukuyama-shi,
Hiroshima 720-0814, Japan
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