16
Curtis 1030 Acuity Manual,
Rev. C
5 — PDO COMMUNICATIONS
5
PDO COMMUNICATIONS
The Curtis Acuity is easily controlled and monitored through two fixed com-
munication packets. Each data packet contains 8 bytes. CANopen calls these
packets Process Data Objects (PDOs). PDO messages have a medium priority.
The PDO communication packets conserve bus bandwidth by bundling
the values of a group of objects into a single message. The content of these
PDOs is fixed, thus simplifying the interface.
The Acuity transmits PDO1, PDO2, and PDO4 continuously. By de-
fault, PDO1 is sent every 100 ms, PDO2 is sent every 5 seconds, and PDO4 is
sent every second. PDO1 and PDO2 transmit periods are configurable using
a CAN object.
PDO1
Byte 1
Byte 2
Byte 3
Byte 4
Byte 5
Byte 6
Byte 7
Byte 8
Battery Battery Battery Battery Temper- Temper- Not
Used SoC
Voltage Voltage Current Current ature ature
LSB MSB LSB MSB LSB MSB
Battery Voltage
Unsigned 16-bit integer. Resolution is hundredths of volts.
Example: A value of 30000 equals 300.00 V.
Battery Current
Signed 16-bit integer. Positive value represents current coming
out of battery (discharge). Units are in tenths of amperes.
Example: A value of +3456 equals 345.6 A of discharge current.
Temperature
Signed 16-bit integer. Units are in hundredths of degrees Celcius.
Example: A value of 5500 equals 55.00°C.
SoC (State of Charge)
Unsigned 8-bit integer. Range is 0 –100%.
PDO2
Byte 1
Byte 2
Byte 3
Byte 4
Byte 5
Byte 6
Byte 7
Byte 8
Historical Historical Historical Historical Historical Historical Historical Historical
Discharge Discharge Discharge Discharge Charge Charge Charge
Charge
Ah LSB
Ah
Ah
Ah MSB
Ah LSB
Ah
Ah
Ah MSB
PDO4
Byte 1
Byte 2
Byte 3
Byte 4
Byte 5
Byte 6
Byte 7
Byte 8
Seconds Minutes Hours
Day
Month
Year [Reserved] [Reserved]
