612699
16
Zoom out
Zoom in
Previous page
1/94
Next page
16 of 94
ELM327
ELM327DSJ Elm Electronics – Circuits for the Hobbyist
www.elmelectronics.com
detected. If there should be a significant number of
errors (due to a hardware or software problem), the
device will go off-line in order to not affect other data
on the bus. The AT CS command lets you see both
the transmitter (Tx) and the receiver (Rx) error counts,
in hexadecimal. If the transmitter should be off (count
>FF), you will see ‘OFF’ rather than a specific count.
CSM0 and CSM1 [ CAN Silent Monitoring off or on ]
The ELM327 was designed to be completely silent
while monitoring a CAN bus. Because of this, it is able
to report exactly what it sees, without colouring the
information in any way. Occasionally (when bench
testing, or when connecting to a dedicated CAN port),
it may be preferred that the ELM327 does not operate
silently (ie generates ACK bits, etc.), and this is what
the CSM command is for. CSM1 turns it on, CSM0
turns it off, and the default value is determined by
PP 21. Be careful when experimenting with this. If you
should choose the wrong baud rate then monitor the
CAN bus with the silent monitoring off, you will disturb
the flow of data. Always keep the silent monitoring on
until you are certain that you have chosen the correct
baud rate.
CTM1 [ set the Timer Multiplier to 1 ]
This command causes all timeouts set by AT ST
to be multiplied by a factor of 1. Note that this currently
only affects the CAN protocols (6 to C). CTM1 is the
default setting.
CTM5 [ set the Timer Multiplier to 5 ]
This command causes all timeouts set by AT ST
to be multiplied by a factor of 5. Note that this currently
only affects the CAN protocols (6 to C).
This command was originally added (as JTM5) to
assist with the retrieving of some J1939 messages.
We have since had several requests to allow it to
affect all CAN modes, and so have modified the JTM5
code and added the new CTM1/CTM5 commands. If
using CTM5, we caution that the Adaptive Timing code
does not monitor changes in the setting, so we advise
turning it off (with AT AT0).
By default, this multiplier is off.
CV dddd [ Calibrate the Voltage to dd.dd volts ]
The voltage reading that the ELM327 shows for an
AT RV request can be calibrated with this command.
The argument (‘dddd’) must always be provided as 4
digits, with no decimal point (it assumes that the
decimal place is between the second and the third
digits).
To use this feature, simply use an accurate meter
to read the actual input voltage, then use the CV
command to change the internal calibration (scaling)
factor. For example, if the ELM327 shows the voltage
as 12.2V while you measure 11.99 volts, then send
AT CV 1199 and the ELM327 will recalibrate itself for
that voltage (it will actually read 12.0V due to digit
roundoff). See page 29 for some more information on
how to read voltages and perform the calibration.
CV 0000 [ restore the factory Calibration Value ]
If you are experimenting with the CV dddd
command but do not have an accurate voltmeter as a
reference, you may soon get into trouble. If this
happens, you can always send AT CV 0000 to restore
the ELM327 to the original calibration value.
D [ set all to Defaults ]
This command is used to set the options to their
default (or factory) settings, as when power is first
applied. The last stored protocol will be retrieved from
memory, and will become the current setting (possibly
closing other protocols that are active). Any settings
that the user had made for custom headers, filters, or
masks will be restored to their default values, and all
timer settings will also be restored to their defaults.
D0 and D1 [ display of DLC off or on ]
Standard CAN (ISO 15765-4) OBD requires that
all messages have 8 data bytes, so displaying the
number of data bytes (the DLC) is not normally very
useful. When experimenting with other protocols,
however, it may be useful to be able to see what the
data lengths are. The D0 and D1 commands control
the display of the DLC digit (the headers must also be
on in order to see this digit). When displayed, the
single DLC digit will appear between the ID (header)
bytes and the data bytes. The default setting is
determined by PP 29.
DM1 [ monitor for DM1s ]
The SAE J1939 Protocol broadcasts trouble codes
periodically, by way of Diagnostic Mode 1 (DM1)
messages. This command sets the ELM327 to
AT Command Descriptions (continued)
16


Need help? Post your question in this forum.

Forumrules


Report abuse

Libble takes abuse of its services very seriously. We're committed to dealing with such abuse according to the laws in your country of residence. When you submit a report, we'll investigate it and take the appropriate action. We'll get back to you only if we require additional details or have more information to share.

Product:

For example, Anti-Semitic content, racist content, or material that could result in a violent physical act.

For example, a credit card number, a personal identification number, or an unlisted home address. Note that email addresses and full names are not considered private information.

Forumrules

To achieve meaningful questions, we apply the following rules:

Register

Register getting emails for Elm 327 at:


You will receive an email to register for one or both of the options.


Get your user manual by e-mail

Enter your email address to receive the manual of Elm 327 in the language / languages: English as an attachment in your email.

The manual is 0,23 mb in size.

 

You will receive the manual in your email within minutes. If you have not received an email, then probably have entered the wrong email address or your mailbox is too full. In addition, it may be that your ISP may have a maximum size for emails to receive.

The manual is sent by email. Check your email

If you have not received an email with the manual within fifteen minutes, it may be that you have a entered a wrong email address or that your ISP has set a maximum size to receive email that is smaller than the size of the manual.

The email address you have provided is not correct.

Please check the email address and correct it.

Your question is posted on this page

Would you like to receive an email when new answers and questions are posted? Please enter your email address.



Info