MoTeC SDL - Manual (Page 15)

MoTeC Overview 13
Communications Overview
The SDL has various communications ports which are used to communicate
with other devices.
USB Communications Port
The USB communications port is used to communicate with a PC. See
Appendix J: USB Wiring for wiring details.
RS232 Communications Port
The RS232 communications port can be connected to an ECU, GPS or
similar device.
CAN Communications Port
The CAN (Control Area Network) communications port can be connected to
other devices with a compatible CAN port. The advantage of CAN is that
many devices can be connected to the CAN bus at once, which allows all
connected devices to communicate with each other, also the CAN port
communicates at very at high speed.
Other MoTeC products that use CAN for intercommunication include the
M800, BR2, PLM and MDD.
Note that these devices communicate at 1Mbit/sec, so any other devices
connected on the CAN bus must also communicate at 1Mbit/sec.
ECU Connection
The SDL can be connected to many Engine Management Systems (ECUs).
This avoids duplication of sensors and allows the SDL to display and log
many ECU parameters.
The ECU may send up to 40 values to the SDL. The update rate of these
values depends on how many values are transmitted, the communications
baud rate and if sent using CAN or RS232. For RS232 the typical update rate
is about 20 times per second and for CAN it is about 50 times per second.
Note that logging the ECU values faster than these rates is unnecessary and
will reduce the total logging time.