Operation Manual

ELM327
ELM327DSJ Elm Electronics – Circuits for the Hobbyist
www.elmelectronics.com
Programmable Parameter Summary (continued)
PRS232 baud rate divisor when pin 6 is high (logic 1)
baud rate (in kbps) = 4000 ÷ (PP 0C value)
For example, 500 kbps requires a setting of 08 (since 4000/8 = 500)
Here are some example baud rates, and the divisor to be used:
68
(38.4)
00 to FF
0C
Notes:
1. The PP 0C value must be provided as hex digits only. The
decimal values (listed above in brackets) are only shown for
your convenience.
2. The ELM327 can only process continuous byte receives at
rates of about 600 kbps maximum. If you need to connect at
a higher rate, add a delay between the bytes to maintain an
average rate of 600 kbps or less.
3. A value of 00 provides a baud rate of 9600 bps.
0D Carriage Return Character R0D00 to FF
Baud Rate
(kbps)
19.2
38.4
57.6
115.2
230.4
PP 0C value
D0 (208)
68 (104)
45 (69)
23 (35)
11 (17)
500
08 (8)
hex (dec)
70 of 94
PP Description Values Default Type
0E 9A
(10011010)
00 to FFPower Control options
Each bit controls an option, as follows:
b7: Master enable 0: off 1: on
if 0, pins 15 and 16 perform as described for v1.0 to v1.3a
(must be 1 to allow any Low Power functions)
b6: Pin 16 full power level 0: low 1: high
normal output level, is inverted when in low power mode
b5: Auto LP control 0: disabled 1: enabled
allows low power mode if the RS232 activity stops
b4: Auto LP timeout 0: 5 mins 1: 20 mins
no RS232 activity timeout setting
b3: Auto LP warning 0: disabled 1: enabled
if enabled, says ‘ACT ALERT’ 1 minute before RS232 timeout
b2: Ignition control 0: disabled 1: enabled
allows low power mode if the IgnMon input goes low
R