Standard Robot Command Interface

Standard Robot Command Interface (SRCI) is a command-based protocol, using PROFINET. It is an open standard developed and maintained by PROFINET International. SRCI defines many commands for basic and advanced use cases. Some are mandatory and some are optional. UR SRCI implements the set of commands known as the “CORE PROFILE” and is built according to version 1.3 of the SRCI standard.

Prerequisites:

Using SRCI with your Universal Robots cobot requires several prerequisites to be met:

• SRCI Controller: With SRCI the PLC takes charge of controlling the cobot’s motions, and therefore, you need a PLC with SRCI Controller functionality. While SRCI is an open standard, it is currently only Siemens supplying this functionality. You need the SIMATIC Robot Integrator software package (version 1.0.1 or later) running on a SIMATIC S7-1500 family of controllers (firmware version 2.8 or later) and configured via the TIA Portal (version 16 or later). For more information please visit: Robot integration - Siemems Global
• UR SRCI URCap: SRCI is not the standard functionality of your UR cobot. You need the UR SRCI URCap, and you need to purchase a license to activate this. Please contact your local sales representative, or request more information here. For the limited release, the license will be free of charge.
• PolyScope 5.15.0: Using the UR SRCI URCap requires PolyScope 5.15.0 or later. Currently, PolyScope X does not support UR SRCI. UR SRCI works with any e-Series cobot arm. The supported versions of PolyScope are downloadable from our download page.

SRCI moves the entire integration of a robotic application to the PLC including the programming of the robot being integrated. With SRCI, functionality for commanding robot motions and for providing an interface for robot programming is added on top of all the common functionalities of the PLC such as workcell logic control and safeguarding. This ‘one to rule them all’ philosophy lifts the burden off the shoulders of the integrator of having to master the many ways different robots are integrated. If you are familiar with PLC programming and SRCI you can integrate any robot.

The current version SRCI URcap v. 0.2.4 supports the limited functionality of the core profile. This includes the following functions:

• RobotTask: Handles multiple mechanisms that are required for the RI to work. It must be
  called once per RA
• ReadRobotData: Read robot-specific data from the RC
• EnableRobot: Enable/Disable robot into RA power state "Enabled"
• GroupReset: Resets and acknowledges info, warning and error messages
• ReadActualPosition: Reads the current position of the TCP relative to the selected or currently used
  tool and frame and the positions of the robot axes
• ReadActualPositionCyclic: Reads the current position of the robot cyclically
• ExchangeConfiguration: Reads and writes specific configuration parameters on RC that are required for
  the RI to work
• ChangeSpeedOverride: Commands a speed override from the PLC to the RC
• ReadMessages: Read pending info, warning and error messages and move them into user data
  block "RobotData"
• GroupJog: Manually jog the TCP or the robot joints.
• MoveLinearAbsolute: Commands an interpolated linear movement of the robot arm to an absolute
  cartesian position
• MoveDirectAbsolute: Commands movement without a specific path (PTP) of the robot arm to an
  absolute cartesian position
• MoveAxesAbsolute: Commands movement without a specific path (PTP) of the robot arm to an
  absolute position specified in Joint Position
• GroupStop: Aborts and deletes all active and buffered commands from the sequence buffer
  of the active sequence
• GroupInterrupt: Interrupts the processing of the currently active sequence (e.g. active
  movements)
• GroupContinue: Continues the processing of the currently active sequence (e.g. interrupted
  movements)
• ReadToolData: Gets the offset of the tool.
• WriteToolData: Sets the offset of the tool.
• ReadFrameData: Gets a user-frame in the workspace of the robot.
• WriteFrameData: Sets a user-frame in the workspace of the robot.

The limited functionality mainly takes away commands for defining payloads, for using a secondary sequence of execution of commands, and for changing the dynamic parameters used during motion.