CAN Communication
The MTS160 supports CANopen, allowing integration with navigation controllers, motor drives, PLCs, and other devices on a CAN bus.
TPDO Communication
The MTS160 transmits sensor data using up to three Transmit Process Data Objects (TPDOs). Each TPDO carries a different class of information and can be enabled or disabled independently.
A TPDO is enabled by assigning it a nonzero transmission period. A period of 0 ms disables that TPDO. Valid period values are 0 to 65535 ms. For any nonzero setting below 5 ms, the actual minimum transmission interval is limited to 5 ms.
"Sense" TPDO
This TPDO reports the main track-following data, including left and right track position, left and right track angle, and sensor status flags. It is the primary TPDO used for real-time navigation control.
Frame Header: 0x180 + NodeID — Byte Count: 5
| Byte | Content | Type | Range |
|---|---|---|---|
| 1 | Left Position | Signed 8-bit | ±80 mm |
| 2 | Right Position | Signed 8-bit | ±80 mm |
| 3 | Left Angle | Signed 8-bit | ±90° |
| 4 | Right Angle | Signed 8-bit | ±90° |
| 5 | Status Flags | Unsigned 8-bit | See below |
Status Flags Byte Detail:
| Bit 7 | Bit 6 | Bit 5 | Bit 4 | Bit 3 | Bit 2 | Bit 1 | Bit 0 |
|---|---|---|---|---|---|---|---|
| Merge Detect | Fork Detect | Crossing Detect | Right Marker Detect | Left Marker Detect | Track Detect & Strength | Track Detect & Strength | Sensor Fault |
Track position and angle values are signed 8-bit integers.
"Marker" TPDO
The "Marker" TPDO delivers precise lateral and longitudinal position data related to point-source markers. This information is critical for last-millimeter positioning.
Frame Header: 0x280 + NodeID — Byte Count: 8
| Bytes | Content | Type |
|---|---|---|
| 1–2 | Left Marker X Position (MSB, LSB) | Signed 16-bit |
| 3–4 | Left Marker Y Position (MSB, LSB) | Signed 16-bit |
| 5–6 | Right Marker X Position (MSB, LSB) | Signed 16-bit |
| 7–8 | Right Marker Y Position (MSB, LSB) | Signed 16-bit |
Position values are signed 16-bit values in tenths of a millimeter (e.g., −235 = −23.5 mm).
"Navicode" TPDO
This TPDO reports the presence and value of Navicode Markers, allowing for the detection and decoding of these localization markers along a navigation path.
Frame Header: 0x380 + NodeID — Byte Count: 3
| Byte | Content | Type | Range |
|---|---|---|---|
| 1–2 | Navicode (LSB, MSB) | Unsigned 16-bit | 0–65535 |
| 3 | Counter | Unsigned 8-bit | 0–255 |
Counter is incremented every time a new Navicode is detected and captured.
Auto-Run Automatic TPDO Transmission
When Auto Run is enabled, the sensor automatically starts CANopen operation at power-up and begins transmitting enabled TPDOs and heartbeat messages according to the configured settings.
When Auto Run is disabled, the sensor waits for CANopen network control and does not automatically start PDO or heartbeat transmission at power-up.
SDO Objects
The MTS160 sensor supports a set of Service Data Objects (SDOs) that allow for parameter setting and sensor configuration.
Zero Setting
Starts zero-level calibration of the internal magnetic sensors. This should be performed after installation and before normal operation.
| Index | Sub | Name | Type | Access |
|---|---|---|---|---|
| 0x2000 | — | ZERO | Unsigned 8-bit | Write Only |
Perform Self-Test
Starts the internal self-test of the 32 magnetic sensing ICs. This command can be used to force a self-test at any time while the sensor is powered.
| Index | Sub | Name | Type | Access |
|---|---|---|---|---|
| 0x2001 | — | SELFTEST | Unsigned 8-bit | Write Only |
Track and Marker Parameters
This SDO is used to modify parameters related to track and marker detection.
| Index | Sub | Name | Type | Access |
|---|---|---|---|---|
| 0x2002 | 1 | TAPE POLARITY | Unsigned 8-bit | Read/Write |
| 0x2002 | 2 | TRACK THRESHOLD | Unsigned 8-bit | Read/Write |
| 0x2002 | 3 | MARKER THRESHOLD | Unsigned 8-bit | Read/Write |
Read Self-Test Results
This SDO provides the results of the most recent self-test, whether performed automatically at power-up or started by the user. It returns the test result together with the minimum and maximum magnetic delta measured across the internal sensing ICs.
| Index | Sub | Name | Type | Access |
|---|---|---|---|---|
| 0x2003 | 1 | SELFTEST RESULT | Unsigned 8-bit | Read Only |
| 0x2003 | 2 | MIN MAGNETIC DELTA | Unsigned 8-bit | Read Only |
| 0x2003 | 3 | MAX MAGNETIC DELTA | Unsigned 8-bit | Read Only |
Heartbeat
The sensor supports the standard CANopen heartbeat mechanism. The heartbeat interval can be set from 0 to 65535 ms. A value of 0 disables heartbeat transmission. For any nonzero setting below 5 ms, the actual minimum heartbeat interval is 5 ms.
Using the Sensor without CANopen
The sensor can be easily operated by Navigation Computers with a CAN interface, even if they do not have a full CANopen Protocol Stack.
To achieve this, enable and set the send rate for the desired TPDO(s) and activate the Auto-Run feature using the Naviq Utility. With Auto-Run enabled, the sensor will start sending the TPDOs and heartbeat at the specified rate, regardless of any other activity on the CAN network.
The data can then be captured and parsed using C or Python code on the navigation computer. Most CAN drivers will store the complete incoming frame, which is structured as follows:
The parsing program first analyzes the header. Performing a bitwise AND operation with 0x7F will isolate the Node ID, which must then be compared with the sensor's Node ID to verify if the frame originated from the MTS160 sensor.
If this is the case, the upper part of the header should be isolated by performing a bitwise AND operation with 0xFF80. It should then be compared with 0x180, 0x280, and 0x380 to determine whether the frame contains TPDO1, TPDO2, or TPDO3.
The payload is then parsed according to the corresponding TPDO mapping described earlier in this manual.
TIP
Sample code can be obtained from the Naviq website.
CANopen EDS File
The Electronic Data Sheet (EDS) file for the MTS160 Magnetic Guide Sensor is provided to facilitate integration into a CANopen network. Containing information such as communication parameters and device-specific settings, the EDS file is necessary for proper configuration and operation within the network. It can be downloaded from the Resources section on the Naviq website at naviq.com.