Contents

Chapter 1
Introduction

The WAGO PLC platform represented by the PFC100 a PFC200 models is supported in REXYGEN starting with version 2.50.5. The support includes integration of Kbus for communication with WAGO I/O modules 750/753 and other standard drivers (Modbus RTU, Modbus TCP/IP, Siemens PLC communication driver, database driver), function block libraries and web user interface. The support includes basic analog and digital I/O modules, persistent memory and indication LED.

Chapter 2
Installation

The runtime modules of the REXYGEN system may be installed by replacing the operating system with an OS image from SD card or by downloading and installing a few packages directly into a running device.

Please follow the instructions in the Getting started guide for the Wago PFC platform.

2.1 Location of files

All REXYGEN runtime configuration and data files are located in the /rex directory. However, this directory name is in fact a symbolic link to the /home/rex directory on the WAGO platform due to the system drive layout. Creation of a user account named "rex" is not recommended due to possible conflicting of names.

Chapter 3
Identification and licensing

The WAGO PFC100 and PFC200 platforms are identified as WAGO PFC, the generic identification is "Generic Linux on ARM". A DEMO license is available for testing and evaluation. A proper license for required functionality has to be obtained for permanent operation. Details about REXYGEN licensing mechanism can be found at
https://support.rexygen.com/help/rexygen-licensing-mechanism.

Chapter 4
Integration into the project

A driver named WagoDrv is available for the WAGO PFC platform. The driver makes accessible I/O modules and some of the LED indicators to the control algorithm. Integration of the driver into a project is done using the IODRV/TIODRV function blocks. Both module name and class name parameters are set to WagoDrv. For details about individual function blocks of the REXYGEN system please refer to [1].

4.1 I/O variables

A simple From/Goto or extended INQUAD, INOCT, OUTQUAD, OUTOCT function blocks may be used to access runtime variables provided by the driver. If the number of block’s inputs/outputs exceeds the number of module channels addressed, excess outputs are set to 0 with BAD quality, excess inputs are ignored. Examples of accessing variables from a control algorithm are provided within REXYGEN Studio. All examples for the WAGO platform are identified as 0102-xx.

The variable names for accessing the data of I/O modules are assembled in following way:

S<X>M<Y> [input/output, double/word/bool] – Refers to the data of a slot number X in which a module of type Y is present. The slots are numbered from 1 starting with the module next to the CPU module. Supply and interconnection modules are not numbered. The signal type is defined by the module referred – boolean for digital inputs/outputs and double for analog inputs/outputs. Example: for I/O module 750-430 or 753-430 the variable has name WG__S1M430. In case of a special module, the type is word and the variable contains the a raw data from the bus. A user has to process the value properly according to the documentation. A list of modules supported by the driver is attached.

S<X>M<Y>C<Z> [input/output, double/word/bool] – Refers to the data of a channel number Z, slot number X in which a module of type Y is present. The channels are numbered according the documentation of a module. Example: channels C1-C8 may be used when referring to the 750-430 I/O module.

S<X>M<Y>W<offset> [vstup/výstup, word] – Refers to the data of a slot number X in which a module of type Y is present. The offset is a word offset from the beginning of module’s process image (see documentation for respective I/O module).

S<X>M<Y>OK [vstup, bool] – Indicates, whether a module Y in slot X is present, configured and fully functional.

A "_" (underscore) character may be added to the variable name and followed by arbitrary text. This part of variable name is intended only for user identification purpose and is ignored during the compilation process.

4.2 Controlling LEDs

Indication LEDs on the front side of PLC may be controlled from a control algorithm using variables with a name in a form:

Led<name>

where <name> identifies a LED. Following LEDs may be controlled : MS, NS, USR, U1-U7. The U1-U7 LEDs are available only on PFC200 platform. Use the GOTO function block with the GotoTag set properly. Example: WG__LedMS.

A LED variable has integer type. Its value corresponds to a LED state. Following LED states are defined:

Notice: The state numbers and LED states may be changed by modifying the
/etc/rexcore/cstdiagnostic.xml file directly on a target WAGO PFC device.

4.3 Meaning of LED indicators

SYS – system state: green – OK, red – ERROR,

RUN – REXYGEN runtime state: green – RUNNING, red – ERROR, yellow – STOP,

I/O – Kbus state: green – RUNNING, red – ERROR/terminal module not connected,

MS, NS, USER, U1-U7 – meaning defined by a user in a control algorithm.

4.4 Global variables

Following global variables are available:

KbusOK [input, boolean] – indicates a correct operation of a system bus (Kbus),

KbusStatus [input, int] – number of a last communication cycle error, 0 = no error; the error number is not compatible with standard REXYGEN error codes – use only for diagnostic purpose,

ModulesOK [input, boolean] – indicates whether all I/O modules used in the algorithm work correctly,

CycleCount [input, int64] – holds the total communication cycle count of the system bus from the start of operation,

KbusAllowControlMode [output, boolean] – switches the system bus into the configurable state. See the WAGO IO Check chapter for more information.

4.5 Mode selector switch

The "Mode selector switch" on a CPU unit starts/stop the control algorithm. Additionally, a control algorithm may be restarted (re-loaded from persistent storage) by pushing the switch to the "reset" position for more than 2 seconds. If the switch is hold in the "reset" for more than 8 seconds, the control algorithm is reloaded and all persistent (retentive) variables are cleared.

Notice: A control algorithm can not be started if a switch is in the "stop" position and a download operation finishes with warning.

4.6 Communication cycle

Internal communication on a system bus (Kbus) between CPU and connected I/O modules is cyclic and synchronous. The bus requires approximately 3 ms to transfer all data in a single cycle. The value may rise if more I/O modules are connected. We don’t recommend to set the communication cycle of a driver to less than 5 ms. The communication cycle is derived from the main executive tick multiplied by the driver factor (tick x driver factor). The cycle length also must not be longer than 50 ms. If the cycle length is longer, the bus watchdog is activated and all I/O modules are reset (outputs are set to 0). An actual cycle length may be obtained from the diagnostic window in REXYGEN Studio.

Chapter 5
WAGO IO Check

WAGO IO Check is a software tool by the WAGO company intended for configuration of I/O modules connected to the PLC. It is possible to connect with WAGO IO Check when a REXYGEN runtime is running. A user may then perform diagnostic and/or configuration operations. (some I/O modules have configuration options, some don’t offer any). Please, see the WAGO IO CHECK documentation for more information.

Notice: It is not possible to perform any configuration operations in the default operation mode of the REXYGEN runtime and only monitoring may be performed. When configuration task are necessary, the GOTO function block that accesses the KbusAllowControlMode variable has to be inserted into algorithm and set to "true". The communication cycle is not terminated when the value of the KbusAllowControlMode variable is changed. If set to "true", configuration operations may be performed.If set back to "false", all modules are re-initialized and the configuration is checked.

Notice: WAGO IO Check can not connect if the REXYGEN runtime or any other runtime is not running on the device.

Chapter 6
Web interface

A standard WEB interface of the REXYGEN runtime is available on port 8008 (http) and 8009 (https). A WAGO WEB interface is available on port 80 (http) and 443 (https).

Chapter 7
Security

We strongly advise to secure the device properly before commissioning including setting of user accounts and passwords, services and encryption.

7.1 User accounts

By default, following user accounts are available on the WAGO PFC platform:

1. In Linux: root/wago and admin/wago.
2. In WAGO WEB interface: admin/wago and user/wago.
3. In REXYGEN runtime: admin/blank password.

The accounts are not connected and must be set individually. Please, change the default password before commissioning by following these steps:

1. In Linux: connect via SSH (PuTTy) using the respective user name and change the password using the passwd command.
2. In WAGO WEB interface: in section Administration.
3. In REXYGEN runtime: connect using REXYGEN Studio and select Target->Change password.

See more information about user accounts and permissions documentation of RexCore [2].

7.2 Services

A WAGO IO Check connection is enabled by default. The connection does not require authentication. The service may be disabled by following command:

/etc/config-tools/config_iocheckport state="disabled"

7.3 HTTPS

Certificate and private key files are created automatically during the startup if those file are not already present. The certificate file is located in /etc/rexcore/rexcore.cer, the private key file is located in /etc/rexcore/rexcore.key. Secured WEB interface of REXYGEN runtime runs on port 8009. A connection may be established by URL in the form: https://device-ip-address:8009.

Chapter 8
Advanced configuration of a web interface

The WEB interface of the REXYGEN runtime may be disabled – see the documentation of RexCore. Alternatively, both REXYGEN runtime and WAGO WEB interfaces may be united using a proxy WEB server. In that case, the WAGO WEB interface service ports have to be changed, for example to ports 8080 (http) and 8433 (https) — see /etc/lighttpd/lighttpd.conf. Then, a proxy server has to be installed. For this purpose, a nginx package is prepared. The configuration file is located in /etc/nginx/nginx-rex.conf.

First, enable the HTTP service in the WAGO WEB interface. Then, install the nginx server by following commands:

wget http://download.rexcontrols.cz/files/wago/<version>/nginx_1.10.3_arm.ipk

ipkg install nginx_1.10.3_arm.ipk

HTTPS protocol may be enabled in the configuration file /etc/nginx/nginx-rex.conf by uncommenting the lines that follow the "uncomment to enable SSL" line. The nginx or the whole device have to be restarted after the configuration is changed. The nginx proxy server uses the same certificate and private key as the REXYGEN runtime by default.

Chapter 9
Other tips

Complete identification of a device:

/etc/config-tools/get_typelabel_value -a

or at http://device-ip-address/api/:platinfo

Miscellaneous information about a device:

/etc/config-tools/get_coupler_details –help

Please, send all questions related to the WAGO PFC platform or the REXYGEN system to our support team at support@rexygen.com.

Appendix A
Supported I/O modules

• Full – Individual signals are provided in units of measurement (volts, milliamps, etc.).
• Partial – Individual signals are provided as data for further processing (using function blocks LIN, GAIN, CNDR, INTSM, etc.). For details about individual function blocks of the REXYGEN system please refer to [1].
• Raw – Raw process image data of the module is available. It is up to the user to parse the data.
• N/A – Module is not supported at all. This status also applies to modules which are not listed here. Contact us for further details.

Bibliography

Documentation reference number: 16076

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