6: Vehicle Control Language & Can - Curtis 1232E Manual

Curtis 1232E/34E/36E/38E/39E & 1232SE/34SE/36SE/38SE Manual, os37.0 – May 2021
The motor command diagrams for the Dual Drive controllers are shown in Figure 7a (for the manager
controller, which controls the Left traction motor) and Figure 7b (for the ancillary controller, which
controls the Right traction motor).
Dual Drive operation is initiated by the steer pot, which is connected to the ancillary controller. The steer
pot wiper voltage is sent in a CAN message to the manager controller (Fig. 7a point A) where the wiper
voltage is converted to steer angle. The Steer_Angle and Mapped_Throttle are processed and produce a
throttle value for the manager traction controller and the ancillary traction controller (which is sent via a
CAN message to the ancillary controller (Fig. 7b point B).
The throttle processing in the manager controller is similar to the throttle processing in a non-dual-drive
controller except for the additions of steer angle dual throttle processing and sending CAN messages to
the ancillary controller for throttle and brake commands. The brake signal can be followed in the manager
from the brake pot input to the Brake_Command. The Dual_Ancillary_Brake_From_Manager variable is
sent from the manager traction controller to the ancillary traction controller via a CAN message (Fig. 7a
point B to Fig. 7b point B).
The throttle processing in the ancillary controller is different from the throttle processing in a non-dual
drive controller because here the manager controller is processing the throttle variables. The Dual_
Ancillary_Throttle_From_Manager (Fig. 7b point B) and Dual_Ancillary_Brake_From_Manager (Fig. 7b
point C) arrive from the manager as shown. The Throttle Pot input on the ancillary is not used for throttle
and may be programmed in VCL for other uses.
VCL is not required to implement the Dual Drive CAN feature. Meaning that for a system not using
VCL, the dual drive manager/ancillary controllers will operate as described above. However, when
VCL is implemented, should the VCL CAN operation be stop or become idle*, use the VCL function
INIT_DUAL_MOTOR_CAN() to restart (re-initialize) the Dual Drive CAN operation, besides using the
STARTUP_CAN() for VCL CAN.
INIT_DUAL_MOTOR_CAN( )
This function initializes (restarts) the dual drive CAN functions.
*VCL functions that either stop or idle the VCL CAN operation will require re-initializing of the
dual drive CAN. Or, if the CANbus turns OFF or stops.
Examples:
1. The VCL function SETUP_CAN() in a VCL program will "stop" the Dual Drive CAN operation,
2. The VCL function SHUTDOWN_CAN () in a VCL program will stop the dual drive CAN
3. If the variable can_error_status = 3, the CANbus is Off (reference SysInfo, "CAN/Nodes Bus Status
NOTE: When using VCL with Dual Drive, the CAN mailboxes CAN3 – CAN6 are required to be
reserved by the OS for Dual Drive operation. Refer to the "CAN Access IDs" section in the SysInfo file.
pg. 14
6 — VEHICLE CONTROL LANGUAGE & CAN
Syntax:
Init_Dual_Motor_CAN()
Parameters: None.
Returns: None.
Error Codes: None.
because it leaves the VCL CAN system in an idle state.
operation, because it stops the VCL CAN system.
Information" section).
6 — VEHICLE CONTROL LANGUAGE & CAN
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