BELT real-valued function BELT real-valued function Syntax BELT (%belt_var, mode ) Function Return information about a conveyor belt being tracked with the conveyor tracking feature. Usage Considerations This option is available only if your system is equipped with the eV+ Extensions option. The BELT system switch must be enabled before this function can be used. The SETBELT instruction is generally used in conjunction with the BELT real-valued function to set the effective belt position to zero. This must be done each time the robot will perform a sequence of motions relative to the belt, and must be done shortly before the first motion of such a sequence. WARNING:
It is important to execute SETBELT each time the robot is going to track the belt, to make sure the difference between the current belt position (as returned by the BELT function) and the belt position of the specified belt variable does not exceed 8,388,607 (^H7FFFFF) during active belt tracking. Unpredictable robot motion may result if the difference does exceed this value while tracking the belt. Parameters %belt_var The name of the belt variable used to reference the conveyor belt. As with all belt variables, the name must begin with a percent symbol (%). mode Control value that determines the information that will be returned.
If the mode is omitted or its value is equal to zero, the BELT function returns the encoder reading in encoder counts of the belt specified by the belt variable. The value returned by this function is limited to an absolute value of 8,388,607 and will roll over to - 8,388,608 after. If the value is equal to -1, the BELT function returns the last latched encoder position in encoder counts of the belt specified by the belt variable. This value equivalent to the value returned by DEVICE(0, enc, stt, 4) except it is not bounded to 8,388,607. eV+Language Reference Guide, v2.x, 18319-000 Rev A Page 85