STIM202 is a cluster of 1, 2 or 3 high accuracy MEMS-based gyros in a miniature package. Any configuration of axes can be provided. Each axis is factory-calibrated for bias, sensitivity and compensated for temperature effects to provide high-accuracy measurements in the temperature range -40°C to +85°C. The unit runs off a single +5V supply.

STIM202 communicates via a standard high-level RS422 interface. The use of a 32 bit RISC ARM microcontroller provides flexibility in the configuration, like choice of output unit, sample rate, LP filter -3dB frequency and RS422 bit-rate and protocol parameters. All configurable parameters can be defined when ordering or set by customer.

When STIM202 is powered up, it will perform an internal system check and synchronise the gyros. As an acknowledgement of the complete power-up sequence, it will provide special datagrams containing data, like part number, serial number, number of active axis and configuration parameters as mentioned above. STIM202 will then automatically proceed to provide measurement data. Hence the simplicity of use is high: just connect power and STIM202 will provide accurate gyro measurements over the RS422 interface.

The measurement data is transmitted as packages of data on a fixed format (datagram) at intervals given by the sample rate. The datagram is in binary coded format in order to have an efficient transfer of data. In addition to the measurement data itself, the datagram contains an identifier, a status byte and a CRC(Cyclic Redundancy Check) byte to provide high degree of fault detection in the transmissions. The status byte will flag any detected errors in the system.

For more advanced users, the gyro may be put in Service Mode. In this mode all the configuration parameters can be intermediately or permanently changed by overwriting the current settings in the flash memory. In Service Mode the commands and responses are in a human readable format; to enable the use of terminal-type software during typical product integration. Service Mode also provides the ability to perform single measurements, perform diagnostics and obtain a higher detail level of detected errors reported in the status byte.

Features:

l  Small size, low weight and low cost

l  ITAR free

l  Insensitive to magnetic fields

l  0.5°/h bias instability

l  0.2°/√h angular random walk

l  ±400°/s angular rate input range

l  1500g shock capability

SPECIFICATIONS:

Parameter	Min	Nom	Max	Unit
Weight		55		g
Input range		±4002		°/s
Resolution		24		bit
Operating temperature	-40		85	°C
Storage temperature	-50		90	°C
Power supply	4.5	5.0	5.5	V
Supply current		200		mA
Start-up time		5		s
Sample Rate			1000	SPS
Dynamic overload			5000	°/s
Mechanical shock			1500	g
Bias instability (Root Allan Variance)		0.5		°/h
Angular random walk (Root Allan Variance)		0.2		°/√h
Bandwidth (-3dB)			262	Hz
Non-linearity (BSL over +/- 200 °/s)		200		ppm
Scale Factor accuracy		±0.2		%
Bias error over temperature gradients		±30		°/h rms
Linear acceleration effect		7		°/h/g
RS422 bit rate			921600	bit/s
Input resistance (termination ON)		120		?
Input resistance (termination OFF)				?
Logic levels NRST and EXT TRIGGER pins	CMOS and TTL compatible