Sundance's communications protocol - SundanceMultiprocessorTechnology/VCS-1 GitHub Wiki

Sundance's communication protocol

Supported frameworks

The protocol is valid for:

  • ROS
  • MQTT

Packet format

destDevice srcDevice command timestamp payloadSz payload

Note that the commands are comma "," separated

Abbreviation Description
dstdevice Destination device.
srcDevice Source device.
command Command.
timestamp Actual timestamp synchronized with a time server
payloadSz Number of variables in the payload
payload Fields required by each command

List of devices

id Description
0 VCS main unit
1 Control unit
2 Subscriber unit 0

Packet flow:

  • Packets sequence:
  • DigitalPortsSetup -> DigitalPortsSetup_errors
  • Setup_PWM -> Setup_PWM_errors
  • PWM -> PWM_errors
  • Digital_write -> Digital_errors
  • Digital_read -> Digital_results -> Digital_errors
  • Analog_write -> Analog_errors
  • Analog_read -> Digital_results -> Digital_errors
  • Digital_write -> Analogue_results -> Analogue_errors
CMD Description VCS Control Unit Subscribers
1 Digital_write dstDevice srcDevice N/A
2 Digital_read dstDevice srcDevice dstDevice
3 Analog_write dstDevice srcDevice N/A
4 Analog_read dstDevice srcDevice dstDevice
5 DigitalPortsSetup dstDevice srcDevice N/A
6 Digital_results srcDevice dstDevice srcDevice
7 Analog_results srcDevice dstDevice srcDevice

List of commands

CMD Description Topic Format
1 Digital_write /FM191/messages 0,1,1,TMSTP,4,TYPE,PORT,VALUE,CREDENTIAL
Type:
0 - DIO
1 - GPIO
2 - LED
2 Digital_read /FM191/messages 0,SRC,2,TMSP,2,TYPE,PORT
Type:
0 - DIO
1 - GPIO
2 - LED
3 Analog_write /FM191/messages 0,1,3,TMSP,3,PORT,VALUE,CREDENTIAL
4 Analog_read /FM191/messages 0,SRC,4,CMD,TMSP,1,PORT
5 DigitalPortsSetup /FM191/messages 0,1,5,CMD,TMSP,44,DIO0_READ?, ... ,GPIO27_READ?,CREDENTIAL
NOTE1: 0 - write, 1 - read
NOTE2: 43 = 15 DIOs and 28 GPIOs
6 Digital_results /FM191/digital/results DST,0,6,TMSP,2,TYPEPORT,VALUE
7 Analog_results /FM191/analog/results DST,0,CMD,TMSP,2,PORT,VALUE
8 Register_Unit /FM191/messages CMD,TMSP,PORT,UTYPE
9 Digital_errors /FM191/digital/results CMD,TMSP,PORT,ERROR_CODE
ERROR_CODES:
0 - no error
10 Analog_errors /FM191/analog/results CMD,TMSP,PORT,ERROR_CODE
ERROR_CODES:
0- no error
11 DigitalPortsSetup_errors /FM191/digitalportssetup/results CMD,TMSP,ERROR_CODE
ERROR_CODES:
0 - no error
12 setup_pwm /FM191/messages CMD,TMSP,FREQ,SCALE
ERROR_CODES:
0 - no error
13 setup_pwm_errors /FM191/pwm/results CMD,TMSP,ERROR_CODE
ERROR_CODES:
0 - no error
14 pwm /FM191/messages CMD,TMSP,PORT,TYPE,VALUE,DURATION^1
ERROR_CODES:
0 - no error
15 pwm_errors /FM191/pwm/results CMD,TMSP,ERROR_CODE
ERROR_CODES:
0 - no error

^1 Duration in clock cycles

List of topics:

  • /FM191/messages
  • /FM191/digital/results
  • /FM191/analog/results
  • /FM191/digitalportssetup/results
  • /FM191/pwm/results

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