Weigh XBot

Use this command to weigh the payload carried by the XBot. This command does not provide a reply immediately, but calculates the weight of the payload for the specified duration.

This command is more repeatable than Payload Weighing, but takes longer to complete.

Fieldbus Interface

PMC_WeighXbot

Name	Data Type	Description

Name	Data Type	Description
Execute	BOOL
XbotID	USINT
Duration	REAL	Duration to measure the weight, in seconds. Recommended value: 0.2
ReturnType	USINT	0: Wait until weighing is done before returning 1: Start weighing only 2: Read weighing result only
PM_Controller	PMControllerType

Name	Data Type	Description

Name	Data Type	Description
Ack	BOOL
Done	BOOL
Busy	BOOL
Aborted	BOOL
Error	BOOL
ErrorID	UINT
Weight	REAL	Payload weight, in kg

Ethernet Interface

PayloadWeighingReturn PayloadWeighingKg(int xbotID, double durationSecs)

Name	Type	Description

Name

Type

Description

xbotID

int

durationSecs

double

Duration to measure the weight, in seconds. Recommended value: 0.2

Name	Type	Description

Name

Type

Description

PayloadWeighingReturn.PmcRtn

PMCRTN enum

PayloadWeighingReturn.WeightKG

float

Weight of the payload, in kg

Conditions

Operating Conditions

Operating Conditions
Preconditions	XBot is in the Idle or Waiting State, at a consistent location
Postconditions	The measured payload is provided in the output

Description

Use this command to weigh the payload carried by the XBot. This command does not provide a reply immediately, but calculates the weight of the payload for the specified duration.

This command is more repeatable than Payload Weighing, but takes longer to complete.

The ReturnType input is used to select the return behaviour of the command:

0: The Weigh Xbot command will block the fieldbus and wait for the results of weighing (based on the Duration specified) before returning a Done signal and the corresponding weight. Other commands cannot be sent while this command is active. This is the default behaviour.

Since ReturnType 0 will block the fieldbus, please keep in mind that starting multiple weighing commands with long durations (for e.g. 4 seconds) at the same time may result in a command timeout for the later commands (Error code: 8201).

1: The XBot will start weighing but the fieldbus is not blocked during that time. Other commands can be sent. Once the weighing is completed, this command will issue the Done signal.
2: When the Done signal is generated by the Weigh Xbot command with ReturnType 1, use this ReturnType to read the result of the weighing.

It is possible to weigh the payload carried by the XBot using the Weigh Xbot command. The resolution is 0.1g, the repeatability is about 0.2g, and accuracy depends on the calibration. Weighing should be completed with Z = 1mm, Rx = Ry = Rz = 0.

The weighing output is position dependent, to get meaningful results, it is best to always do the weighing from the same position. For all XBots, position it so that 2 edges of the XBot are aligned with 2 edges of the Flyway. For example, for M3-06 (120mm x 120mm), the positions that will provide the most accurate weighing result is at the 4 corners of the Flyway: (X,Y) = (60mm,60mm), (60mm,180mm), (180mm,60mm) and (180mm,180mm).

Changelog

PMC v117.10.10 - Added ReturnType: the user can now choose whether or not the command waits for weighing to complete before returning.