CANopen object dictionary
Reference. Source of truth: uc2-ESP/lib/uc2_od/OD.c (hand-maintained). Every role (master, satellites, bridges) runs the same OD; what a node does with an object depends on its build.
EDS files
DOCUMENTATION/openUC2_satellite.eds is generated from tools/canopen/uc2_canopen_registry.yaml, not from OD.c. It lists 21 objects that do not exist on the device, wrong identity/heartbeat/PDO defaults, and wrong sizes for 0x2609/0x260A. openUC2_satellite_new.eds is an older snapshot. Neither the firmware nor uc2canopen loads an EDS. Use the tables below.
Bus and services
| Item | Value |
|---|---|
| Stack | CANopenNode v4.0 on ESP32 TWAI |
| Bitrate | 500 kbit/s, fixed (LSS bit-timing changes are ignored) |
| Identifiers | 11-bit |
| NMT | no NMT master; every node boots straight to OPERATIONAL |
| Heartbeat | every node, 1000 ms (0x1017); no heartbeat consumer configured |
| SDO | one server per node: request 0x600+n, response 0x580+n; block transfer supported (OTA) |
| SYNC | 0x080, sent only by the master during a strobed sweep |
| EMCY | 0x080+n; codes 0xFF01–0xFF07 = closed-loop axis faults |
| LSS | slave only; serial number = lower 32 bits of the MAC |
Identity 0x1018 | vendor 0x00001234, product 0x1, revision 1 (placeholders) |
PDOs
The master sends commands only via SDO. PDOs carry feedback.
| PDO | COB-ID | Producer | Content (bytes) | Timing |
|---|---|---|---|---|
| TPDO1 | 0x180+n | every node | 0x2001:01 position i32 · 0x2004:01 status u8 · 0x2016:01 homing u8 (6) | on change, inhibit 10 ms, event 500 ms |
| TPDO2 | 0x280+n | GPIO satellite (60), PTZ bridge (61) | 0x2300:01–04 4× u8 · 0x2310:01–02 2× u16 (8) | on change only |
| TPDO3 | 0x380+n | motor satellites with sync latch on | 0x200C:01 latched position i32 · 0x200D:01 count u16 (6) | after each SYNC |
| RPDO1–4 | 0x18A–0x18D | consumed by every node | TPDO1 of nodes 10–13 → slot 0–3 of 0x2001/0x2004/0x2016 | — |
Status byte (0x2004): bit 0 = running, bit 1 = 1 Hz toggle (keep-alive). Homing byte (0x2016): 0 idle, 1 homing, 2 done, 3 timeout.
Conventions
- Arrays: sub 0 = count (ro), sub 1…N = elements.
- Motor-type arrays: sub = stepperid + 1 (A = 1, X = 2, Y = 3, Z = 4). A single-axis motor satellite maps any sub to its one physical axis for move, home and hard-limit objects.
0x2005and0x2020–0x2026are read from sub 2 only. - Laser arrays: sub = channel + 1.
- All manufacturer values are 0 after boot.
- "doorbell" = writing the value triggers an action; the node clears it.
Manufacturer objects
Motor 0x2000–0x200E
| Index | Name | Type | Acc | Meaning |
|---|---|---|---|---|
0x2000 [4] | target_position | I32 | rw | steps |
0x2001 [4] | actual_position | I32 | ro* | steps (TPDO1) |
0x2002 [4] | speed | U32 | rw | steps/s, sent signed (sign = jog direction) |
0x2003 | command_word | U8 | rw | doorbell: bit n (0–3) = start slot n, bit n+4 = stop slot n |
0x2004 [4] | status_word | U8 | ro* | bit 0 running, bit 1 keep-alive toggle |
0x2005 [4] | enable | U8 | rw | 1 = driver on |
0x2006 [4] | acceleration | U32 | rw | steps/s²; 0 = keep previous |
0x2007 [4] | is_absolute | U8 | rw | 0 relative, 1 absolute |
0x200B [4] | is_forever | U8 | rw | 1 = jog until stop |
0x200C [4] | sync_position | I32 | ro | position latched at SYNC (TPDO3) |
0x200D [4] | sync_count | U16 | ro | SYNCs latched since enable |
0x200E [4] | sync_latch_enable | U8 | rw | ≠ 0 enables latch + TPDO3, resets count |
ro* = declared rw in OD.c; treat as read-only. 0x2008/0x2009 (min/max position) and 0x200A (jerk) exist but are not used.
Homing 0x2010–0x2016
| Index | Name | Type | Meaning |
|---|---|---|---|
0x2010 [4] | command | U8 | doorbell: 1 = home, 2 = hard home (new) |
0x2011 [4] | speed | U32 | steps/s (max speed = 2 × speed) |
0x2012 [4] | direction | I8 | −1 / 1 |
0x2013 [4] | timeout | U32 | ms |
0x2014 [4] | endstop_release | I32 | steps |
0x2015 [4] | endstop_polarity | U8 | 0 NO, 1 NC |
0x2016 [4] | status | U8 | 0 idle, 1 homing, 2 done, 3 timeout (TPDO1) |
TMC2209 and hard limits 0x2020–0x2032
| Index | Name | Type | Meaning |
|---|---|---|---|
0x2020 [4] | microsteps | U16 | 0 = keep default |
0x2021 [4] | rms_current | U16 | mA |
0x2022 [4] | stallguard_threshold | U8 | |
0x2023/0x2024 [4] | coolstep_semin / semax | U8 | |
0x2025/0x2026 [4] | blank_time / toff | U8 | |
0x2027 [4] | stall_count | U32 | not populated |
0x2030 [4] | hardlimit_command | U8 | doorbell: 1 = clear trip |
0x2031 [4] | hardlimit_enabled | U8 | |
0x2032 [4] | hardlimit_polarity | U8 |
Closed-loop axis 0x2040–0x204B (motor satellites with encoder)
| Index | Name | Type | Acc | Meaning |
|---|---|---|---|---|
0x2040 | measured_steps | I32 | ro | encoder position in steps |
0x2041 | position_error_steps | I32 | ro | |
0x2042 | mode | U8 | rw | 0 open loop, 1 monitor, 2 correct, 3 servo |
0x2043 | health | U8 | ro | |
0x2044 | fault | U8 | ro | 0 none … 7 encoder noise |
0x2045 | reset | U8 | rw | doorbell 1–3 |
0x2046/0x2047 | calibrated / referenced | U8 | ro | |
0x2048 | calibrate | U8 | rw | doorbell |
0x2049 | counts_per_step_q16 | I32 | rw | Q16.16 |
0x204A | backlash_steps | I32 | rw | |
0x204B | raw_counts | I32 | ro |
Laser 0x2100–0x210A
| Index | Name | Type | Meaning |
|---|---|---|---|
0x2100 [4] | pwm_value | U16 | duty, applied on change |
0x2107 [4] | strobe_enable | U8 | new. 1 = one flash per SYNC; node writes 0 back if refused |
0x2108 [4] | strobe_delay_us | U32 | new. µs after SYNC |
0x2109 [4] | strobe_width_us | U32 | new. µs |
0x210A [4] | strobe_count | U32 | new. flashes fired (ro) |
0x2101–0x2103 (max value, PWM frequency, resolution) and 0x2106 (safety state) exist but are not used.
LED array 0x2200–0x2221
| Index | Name | Type | Meaning |
|---|---|---|---|
0x2200 | mode | U8 | 0 off, 1 fill, 2 left, 3 right, 4 top, 5 bottom half; others → fill |
0x2201 | brightness | U8 | 0–255 (0 ignored) |
0x2202 | uniform_colour | U32 | 0x00RRGGBB |
0x2210 | pixel_data | DOMAIN | N × {r,g,b}, ≤ 256 px (segmented SDO) |
0x2211 | single_pixel | 5 bytes | u16 index (LE), r, g, b |
0x2212 | shape | 5 bytes | shape (0 rings, 1 circle), radius, r, g, b |
0x2220 | pattern_id | U8 | starts a pattern |
0x2221 | pattern_speed | U16 |
0x2203 (pixel count) is not populated.
GPIO satellite 0x2300–0x2354
| Index | Name | Type | Meaning |
|---|---|---|---|
0x2300 [8] | digital_input_state | U8 | sub 1 E-stop, 2–3 inputs, sub 4 flags (bit 0 collision trip, bit 1 E-stop). TPDO2 |
0x2301 [8] | digital_output_command | U8 | sub 1–2 = DO1/DO2; 0xFF = pulse |
0x2310 [8] | analog_input_value | U16 | sub 1 filtered, sub 2 raw ADC. TPDO2 |
0x2330 | collision_reference | U16 | ADC counts (manual baseline) |
0x2331 | collision_threshold | U16 | ADC counts |
0x2332 | collision_sensitivity | U8 | consecutive samples |
0x2333 | collision_command | U8 | 1 calibrate, 2 auto, 3 manual |
0x2334/0x2336 | collision_mean / sigma | U16 | ro |
0x2335 | collision_mode | U8 | 0 auto, 1 manual |
0x2350 | i2c_command | 40 bytes | addr7, flags (bit 0 STOP), rd_len, wr_len, delay_ms, data… |
0x2351 | i2c_trigger | U8 | ≠ 0 executes |
0x2352 | i2c_status | U8 | 0 idle, 1 busy, 2 ok, 0x80|err |
0x2353 | i2c_response | 40 bytes | read data |
0x2354 | i2c_resp_len | U8 | valid bytes in 0x2353 |
The PTZ bridge reuses 0x2300 sub 1–4 for key events (type, arg, sequence, 0x80 marker). 0x2340 (encoder position) is not populated.
System 0x2500–0x250A
| Index | Name | Type | Acc | Meaning |
|---|---|---|---|---|
0x2500 | firmware_version | VSTRING 64 | ro | |
0x2501 | board_name | VSTRING 64 | ro | published image name, e.g. esp32_UC2_canopen_slave_motor_release_motX.bin |
0x2503 | uptime_seconds | U32 | ro | |
0x2504 | free_heap_bytes | U32 | ro | |
0x2505 | can_error_counter | U32 | ro | not populated |
0x2507 | reboot_command | U8 | rw | 1 = reboot after 200 ms |
0x2508 | build_timestamp | VSTRING 32 | ro | |
0x2509 | mac_address | VSTRING 18 | ro | AA:BB:CC:DD:EE:FF |
0x250A | commanded_node_id | U8 | rw | 1–127; saved to NVS, node restarts CANopen after 250 ms under the new ID |
Galvo 0x2600–0x2610
| Index | Name | Type | Meaning |
|---|---|---|---|
0x2600 [2] | target_position | I32 | X/Y, DAC 0–4095 |
0x2602 | command_word | U8 | 1 goto, 2 line, 3 raster, 4 stop, 5 e-stop |
0x2603 | status_word | U8 | bit 0/1 = running |
0x2604 | scan_speed | U32 | sample period in µs |
0x2605/0x2606 | n_steps_line / n_steps_pixel | U16 | nx / ny |
0x2607 | d_steps_line | U16 | bidirectional flag |
0x2608 | d_steps_pixel | U16 | line settle samples |
0x2609/0x260A | t_pre_us / t_post_us | U16 | pre / fly samples |
0x260B/0x260C | x_start / y_start | I32 | |
0x260D/0x260E | x_step / y_step | I32 | |
0x260F | camera_trigger_mode | U8 | camera trigger enable (enable_trigger) |
0x2610 | points_data | DOMAIN | {u8 trigger, u16 n} + n × {u16 x, u16 y, u32 dwell_us}, n ≤ 256 |
0x2601 (actual position) is not populated.
Firmware update 0x2F00–0x2F05
| Index | Name | Type | Meaning |
|---|---|---|---|
0x2F00 | firmware_data | DOMAIN | image, SDO block download |
0x2F01 | firmware_size | U32 | write starts the update; 0 aborts; max 0x140000 |
0x2F02 | firmware_crc32 | U32 | zlib CRC-32 of the image; 0 skips the check. Write before 0x2F01. |
0x2F03 | status | U8 | 0 idle, 1 receiving, 2 verifying, 3 complete, 0xFF error |
0x2F04 | bytes_received | U32 | |
0x2F05 | error_code | U8 | 1 no partition, 2 begin, 3 write, 4 CRC, 5 commit, 6 size 0, 7 too large |
The node reboots into the new image 2 s after status 3. A transfer idle for 30 s is aborted.
In the EDS but not on the device
0x2104, 0x2105 (despeckle), 0x2204, 0x2205 (LED layout), 0x2302, 0x2311, 0x2320 (DIO mask, filtered ADC, DAC), 0x2341, 0x2342 (encoder), 0x2400–0x2403 (joystick), 0x2502 (module bitmask), 0x2506 (CPU temperature), 0x2700–0x2705 (PID). SDO access returns abort 0x06020000.