ACOPOS uses gearbox data for two distinct purposes: channel-level axis scaling and motor-level load limitation. Configure each location according to its function; entering a ratio in one location does not replace the other.
Channel gearbox settings control axis scaling
The gearbox ratio in the ACOPOS channel defines the relationship between motor revolutions and engineering units for axis position and speed. The supported scaling relationship is:
Axis units = (Gearbox/Input motor revolutions ÷ Gearbox/Output) × ReferenceDistanceBecause this calculation only establishes scaling, setting Gearbox/Output to 1 and incorporating the actual output factor into ReferenceDistance produces equivalent scaling. This mathematical equivalence does not establish the motor-side data required for torque limitation.
Motor gearbox settings support load limitation
Enter the gearbox's actual ratio in the motor parameters. ACOPOS uses this physical relationship when applying gearbox limitations such as peak output torque. Do not substitute a scaling-only ratio or a ratio algebraically absorbed into ReferenceDistance at this level.
| Configuration location | Purpose | Required value |
|---|---|---|
| ACOPOS channel | Scale axis position and speed into engineering units | A ratio and ReferenceDistance combination that produces the required unit scaling |
| Motor parameters | Support gearbox load and output-torque limitation | The gearbox's actual physical ratio |
Choose between configured and runtime load limits
A load limit configured in the gearbox settings remains independent of application mode settings and is suited to a constant gearbox protection limit. The LimitLoad input associated with MpAxisBasic is intended for applications that enable or vary torque limitation in selected operating situations.
The runtime load-limit value refers to the motor shaft. Therefore, a gearbox peak-output-torque rating cannot be entered directly unless it has first been transformed to the corresponding motor-shaft value. The evidence does not provide a complete conversion rule or gearbox efficiency, so obtain the required mechanical data before calculating that value. The supporting material also refers to MC_BR_LimitLoad; confirm the applicable interface in the installed B&R help rather than assuming that name and the MpAxisBasic input are interchangeable.
Configure and verify the two functions
- Set the ACOPOS channel ratio and
ReferenceDistanceto express axis position and speed in the required engineering units. - Enter the actual gearbox ratio in the motor parameters so gearbox load limitations use the physical transmission ratio.
- Use the gearbox configuration for a constant mechanical limit, or use the runtime
LimitLoadinterface when the application must change the limit between machine modes. - Verify that commanded motion produces the expected engineering-unit position and speed, then confirm that the selected load limit is expressed at the shaft referenced by its configuration interface.
Some earlier motor configuration trees may not expose the gearbox setting. The evidence reports that the setting became available for every motor with the latest motor upgrades, but it does not identify an Automation Studio version, motor revision, or upgrade package. If the node is absent, verify that the installed motor definition is current before concluding that the motor is unsupported.
FAQ
Does the ACOPOS channel gearbox ratio limit torque?
No. The channel ratio is used for axis position and speed scaling. Configure the actual physical ratio in the motor parameters for gearbox load and peak-output-torque limitation.
When should I use MpAxisBasic LimitLoad instead of the gearbox limit?
Use the gearbox setting for a constant limit that remains independent of machine modes. Use the runtime LimitLoad interface when the application must enable or vary the limitation in specific operating situations.
Why is the gearbox setting missing from my motor configuration?
The available evidence indicates that later motor upgrades expose the gearbox setting for every motor, but it provides no exact version. Check whether the installed motor definition or upgrade is current.