PROFINET Protocol
PROFINET is an Industrial Ethernet network protocol that allows controllers such as PLCs to communicate with sensors. Sensors are PROFINET IO devices with Conformance Class A.
GoPxL supports PROFINET communication to provide system state, sensor group state, stamp, and measurement output data to a PLC, as well as accept incoming commands. GoPxL operates as a PROFINET IO-Device, and a PLC that connects to it acts as the PROFINET IO-Controller. All communication is initiated by the PLC, with GoPxL responding to the PROFINET requests.
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GoPxL supports PROFINET on-sensor and on GoMax NX. PROFINET is not currently supported on PC instances of GoPxL. This functionality is planned for the near future. |
While the PROFINET protocol includes several types of requests, the two basic operations are reading and writing PROFINET objects. Commands are invoked by the PLC sending set requests. Data is requested by the PLC by sending get requests for PROFINET objects.
Connections Map
The PROFINET protocol supports the following objects.
Assembly Objects
A register assembly is a container that contains register blocks. This is a one-to-one mapping, which means each PROFINET module will have a corresponding control framework register assembly. These modules are added to the GoPxL irrespective of the selection of register assembly, but the data is added to this PROFINET module based on the selection of register assembly.
|
PROFINET Module Name |
Register assembly |
Supported Register Block Types |
Service |
Instance ID | Slot Number |
|---|---|---|---|---|---|
| Command input module | Control Input register assembly | "ControlInput" | Write | 0x30 | 1 |
| Command output module | Control Output register assembly | "ControlOutput" | Read | 0x31 | 2 |
| System State module | System State register assembly | "System" | Read | 0x32 | 3 |
| Stamp module | Sample State register assembly |
"Stamp" |
Read | 0x33 | 4 |
| Measurement module | Sample State register assembly |
"Measurement " |
Read | 0x34 | 5 |
| Sensor Group State module | Sensor Group State register assembly | "Scanner" | Read | 0x35 | 6 |
The PROFINET protocol supports various block types. Each block type can be either an input block or an output block. Input blocks contain write-only objects and are used by the PROFINET IO-Controller to send commands such as starting or stopping a scan. Output blocks contain read-only objects and are used to store various types information, such as control, system, and sensor group state data as well as scan output data (stamp and measurements).
Supported Block Types
The block types supported by the PROFINET protocol are listed in the table below. The size field indicates the number of registers that each block type requires.
|
Block Type |
Read or Write only? |
Size (number of PROFINET registers) |
Description |
|---|---|---|---|
| "ControlInput" | WO | 67 |
Command message set by the PROFINET IO-Controller. |
| "ControlOutput" | RO | 3 | Result data corresponding to a command that was written to the Control Input block. |
| "System" | RO | 76 |
Information about the LMI device. |
| "Scanner" | RO | 18 | Information about a specific sensor group. |
| "Stamp" | RO | 33 |
Stamp message information. |
| "Measurement" | RO | 5 | Measurement data of a scan output measurement data message. |
Control Input
The input of the Control Input Block contains the fields described below:
|
Field |
Type |
Address offset |
Description |
|---|---|---|---|
| Command Sequence Number | 16u | 0 |
The command sequence number is set by the external IO-Controller to uniquely identify a command request. This number is sent back in the Control Output. This is an optional field but is recommended that PROFINET IO-Controllers use this to help the IO-Controllers correlate the Command Status in the Control Output with a specific command request in Control Input. |
| Command Identifier | 8u | 2 |
Identifies the requested action from the external client. Supported actions: 0 = No Command 1 = Start Scanning 2 = Stop Scanning 3 = Align Sensor Group 4 = Clear Alignment 5 = Load Job File 6 = Software Trigger
|
| Command Arguments |
Array[8u] |
3 |
Arguments for commands that require arguments. For the Load Job File command, the command arguments will contain the null terminated job file name. The job file name must not include the job file extension. The job extension is automatically appended by the PROFINET IO-Device. This field takes up a maximum of 64 registers. Each byte contains a single character. |
Control Output
The output of the Control Output Block contains the fields described below:
|
Field |
Type |
Address offset |
Description |
|---|---|---|---|
| Command Sequence Number | 16u | 0 | The command sequence number received from the IO-Controller in the Control Input. |
| Command Status | 8u | 2 |
Status of the command, referenced by the Command Sequence Number. 0 = No Command Received 1 = In Progress 2 = Success 3 = Fail |
System State
The output of the System State Block contains the fields described below:
|
Field |
Type |
Address offset |
Description |
|---|---|---|---|
| System Uptime | 64u | 0 | Amount of time the application has been running, in seconds. |
| System State | 8u | 8 |
Whether system is running or not. 0 = System is stopped 1 = System is running |
| Current Job File Name Length | 8u | 9 | Number of characters in the current job file name. |
| Current Job File Name | Array[8u] | 10 |
Name of the job file currently loaded into the system, including extension. Maximum length of job file name is 64 characters. Each register contains a single character. Job file name is NOT null terminated. |
| Buffer Count | 8u | 74 |
The current amount of buffered scan output data when buffering is enabled. |
| Buffer Overflow | 8u | 75 |
A value of 0 indicates that no overflow has occurred. A value of 1 indicates that overflow occurred and data is being lost. |
Sensor Group State
The output of the Scanner (Sensor Group) Block contains the fields described below:
|
Field |
Type |
Address offset |
Description |
|---|---|---|---|
| Current Encoder Position | 64s | 0 | The current encoder position. |
| Current Sync Time | 64u | 8 |
Current time of the clock used to stamp all scan output messages, in microseconds. |
| Alignment State | 8u | 16 |
Indicates whether all devices under the sensor group are aligned (that is, all devices in the sensor group have a non-identity transform matrix). 0 = Not Aligned 1 = Aligned 2 = Aligning |
| Laser Enabled | 8u | 17 |
Whether one or more devices under a sensor group has its laser enabled to be able to turn on. 0 = All devices' lasers are disabled and cannot turn on 1 = One or more devices' lasers can be turned on
|
Stamp
The output of the Stamp Block contains the fields described below:
|
Field |
Type |
Address offset |
Description |
|---|---|---|---|
| Z Position | 64s | 0 | Encoder position at time of last index pulse of last frame. |
| Encoder Position | 64s | 8 | Encoder position of last frame when the image data was scanned/taken. |
| Time | 64u | 16 | Time stamp, in microseconds, of last frame. |
| Frame Index | 64u | 24 |
The frame number of the last frame. |
| Digital Input States | 8u | 32 |
Digital input states of last frame. Bit 0: State of digital input 1 on master or sensor Bit 1: State of digital input 2 on master or sensor |
Measurement
The output of the Measurement Block contains the fields described below:
|
Field |
Type |
Address offset |
Description |
|---|---|---|---|
| Value | 32s | 0 |
Measurement value. This value is the actual measurement value multiplied by 1000. If the measurement value is invalid, the 32-bit value is set to 0x80000000. |
| Decision | 8u | 4 |
Measurement decision. Bit 0: 0 = Fail 1 = Pass Bit 1: 0 = Decision value is valid 1 = Decision value is invalid |