Campbell Hausfeld SDM-CAN - Manual (Page 8)

SDM-CAN CAN-Bus Interface User Guide
other SDM-CAN interfaces) which might, for instance, be on other CAN-Bus
networks in the same vehicle.
In addition to connectors to the CAN network and the datalogger, an RS232 port
is also provided both for diagnostics and operating system upgrades.
1.2 Specifications
1.2.1 General Features and Specifications
• Uses Campbell Scientific’s SDM communication protocol to communicate
with the datalogger via a three wire serial multidrop connection. Support is
planned for CR10X, CR23X, CR7, CR5000 and CR9000 dataloggers.
• Up to 16 units can be used per datalogger, with the modules’ SDM address set
by rotary switch.
• CAN 2.0A and 2.0B active and passive modes supported
• Up to 1Mbaud max data rate. Standard baud rates supported are 1M, 800K,
500K, 250K, 125K, 50K, 20K and lower. Other non-standard baud rates may
be possible – please contact Campbell Scientific.
• Receive and transmit up to 128 different data values from up to 128 CAN
ID’s.
• Build and send a CAN data frame.
• Send Remote Frame Requests.
• Send data frame in response to an external Remote Frame Request.
• Supports a number of power down modes to allow power saving in power
critical applications.
• All configuration of the interface is specified within the user’s datalogger
program.
• LED status flash at power up
• Additional I/O port for signalling to the datalogger that data is available,
e.g. using an interrupt function.
• Has a 9 pin, DCE RS232 port with auto baud rate detection (1200 to
115200) for diagnosis and operating software download.
• Standard operating temperature range (tested), -25ºC to +50ºC. Can be used
over an extended temperature range – contact Campbell Scientific for details.
• High speed block mode for fast data collection.
• Buffer assisted burst mode for capturing back to back high speed CAN data.
• Buffer’s support data frame filtering and triggering.
1.2.2 Electrical Specifications
• Power supply range: 7 to 26V DC.
• Optional (switch selectable) galvanic isolation between the datalogger and the
CAN-Bus. The minimum isolation breakdown is 50V – this barrier is for
signal isolation only, i.e. it is not a safety barrier.
• Hitachi H8S,16 bit CPU clocked at 10MHz.
• Uses the latest Philips SJA1000 CAN controller clocked at 16MHz.
• CAN-Bus physical interface using Philips PCA82C251 driver for 1Mbaud
capability, for use in 12V or 24V systems.
• CAN-Bus physical connection conforms to CIA draft standard 102 version 2,
9 pin D connector. (The interface will differ from this standard only with
respect to pin 9, which outputs 5V DC instead of 7-13V DC.)
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