The SDM-INT8 outputs timing data to a Campbell Scientific datalogger. The datalogger can process the timing data to calculate RPM, duty cycle, velocity, crank angle, etc.
The SDM-INT8 has eight channels that are individually programmed to record the timing of input voltage transitions (events). It uses this information to output:
The datalogger enables individual modules through an addressing scheme; up to 16 SDM-INT8s can be connected to one datalogger. After a module is enabled, it operates independently of the datalogger until additional commands are received or results are transmitted.
a - The maximum frequency specification for high resolution (32-bit) values assumes all eight channels are used.
b - The maximum frequency specifications for low resolution (16-bit) values is for the execution interval averaging only.
The SDMINT8 instruction controls the SDM-INT8 operation in CRBasic. Instruction 101 controls the SDM-INT8 operation in Edlog.
*For the CR3000 and CR5000, SDMs are connected to the ports labeled SDM-C1, SDM-C2, and SDM-C3.
#For the CR7, SDMs connect to the C1, C2, and C3 terminals provided on the 700X control module (after Sept 1996).
†On the CR9000X, SDMs connect to ports provided on the CR9032 CPU module.
♣On the CR9000, SDMs connect to ports provided on the CR9080 PAM module.
The SDM-INT8 draws 20 mA. In most applications, the datalogger’s sealed rechargeable power supply can be used. The datalogger’s alkaline power supply has sufficient capacity to operate the SDM-INT8 during short-term installations only.
The SDM-INT8 should be housed in an environmental enclosure. A bracket is shipped with the SDM-INT8 for mounting it to an enclosure backplate.