8.1. Real-time Ethernet Driver selection

The EC-Monitor currently supports a variety of different Real-time Ethernet Driver modules, each of which contained in a single library file, which is loaded by the core library dynamically. The EC-Monitor shipment consist of a core library and one (or more) libraries each containing support for one specific Real-time Ethernet Driver module (type of hardware card). Which library actually is loaded, is depending on the Real-time Ethernet Driver parameters at runtime.

Real-time means operating directly on the network device’s register set instead of using the operating system’s native driver.

The principle of Real-time Ethernet Driver selection is that the name of the Real-time Ethernet Driver (Real-time Ethernet Driver Identification) is used to determine the location and name of a registration function, which is called by the EC-Monitor and registers function pointers which allow access to the Real-time Ethernet Driver functional entries.

The EtherCAT® Real-time Ethernet Driver will be initialized using a Real-time Ethernet Driver specific configuration parameter set. A pointer to this parameter set is part of the EC-Monitor initialization settings.

The EC-Monitor supports two Real-time Ethernet Driver operating modes: - Interrupt mode all received Ethernet frames will be processed immediately in the context of the Real-time Ethernet Driver receiver task. - Polling mode the EC-Monitor will call the Real-time Ethernet Driver receiver polling function prior to processing received frames.

8.1.1. Real-time Ethernet Driver and PHY OS Driver

Some operating systems, e.g. Linux and Xenomai, provide drivers for most common Ethernet controllers and their related physical transceivers (PHY). The manufacturer specific PHY circuits can be handled by a dedicated driver. Using the PHY OS Driver interface it is possible to use the manufacturer’s dedicated PHY driver without modification of the Real-time Ethernet Driver driver. Depending on the hardware architecture, an additional module from acontis, e.g. atemsys for Linux, grants access to the MDIO bus to the OS drivers, or request MDIO operations from the OS drivers.

Note

Real-time Ethernet Driver modules not listed here may be available if purchased additionally

8.1.2. Real-time Ethernet Driver selection and initialization

The different Real-time Ethernet Driver modules are selected and parameterized by a common structure EC_T_LINK_PARMS shared by all Real-time Ethernet Driver and a Real-time Ethernet Driver specific structure, pointed to by an element within the common structure. This parameter set is given to EC_T_INIT_MONITOR_PARMS::pLinkParms with the call of emonInitMonitor().

struct EC_T_LINK_PARMS

Public Members

EC_T_DWORD dwSignature

[in] Signature of the adapter specific structure containing the EC_T_LINK_PARMS structure

EC_T_DWORD dwSize

[in] Size of the adapter specific structure containing the EC_T_LINK_PARMS structure

EC_T_LOG_PARMS LogParms

[in] Logging parameters

EC_T_CHAR szDriverIdent[EC_DRIVER_IDENT_NAMESIZE]

[in] Name of Link Layer module (driver identification) for Link Layer Selection

EC_T_DWORD dwInstance

[in] Instance of the adapter. if EC_LINKUNIT_PCILOCATION is set: contains PCI address

EC_T_LINKMODE eLinkMode

[in] Mode of operation

EC_T_CPUSET cpuIstCpuAffinityMask

[in] Interrupt service thread CPU affinity mask

EC_T_DWORD dwIstPriority

[in] Task priority of the interrupt service task (not used in polling mode)

EC_T_DWORD dwIstStackSize

[in] Task stack size

EC_T_DWORD dwLinkSpeed

[in] 10, 100, 1000 Mbit\s

EC_T_LINKLAYER_TIMINGTASK oLinkLayerTimingTask

[in] LinkLayer timimg task parameters

EC_T_CHAR szLoadPath[EC_DRIVER_PATH_MAXLEN]

[in] path from which the libraries should be loaded

struct EC_T_LINKLAYER_TIMINGTASK

Public Members

EC_T_LINKLAYER_TIMING eLinkLayerTiming

[in] LinkLayer timing task mode

EC_T_DWORD dwCycleTimeUsec

[in] Cycle time between 2 pfnStartCycle calls in us. Will be set by the master stack for the linklayer.

EC_T_LINK_STARTCYCLE_CALLBACK pfnStartCycle

[in] Callback function called cyclically according dwCycleTimeUsec

EC_T_VOID *pvStartCycleContext

[in] Context passed to each pfnStartCycle call

EC_T_DWORD dwTtsSendOffsetUsec

[in] Time between pfnStartCycle call and TTS frame transmission

EC_T_UINT64 nSystemTime

[in] System

8.1.3. Real-time Ethernet Driver instance selection via PCI location

For some operating systems it is possible to address the Real-time Ethernet Driver instance using its PCI address as an alternative. To do this, EC_LINKUNIT_PCILOCATION (0x01000000) and the PCI location must be set as EC_T_LINK_PARMS::dwInstance.

On Linux the PCI address can be shown using e.g.:

lspci | grep Ethernet

00:19.0 Ethernet controller: Intel Corporation Ethernet Connection I217-LM (rev 04)
04:00.0 Ethernet controller: Intel Corporation 82574L Gigabit Network Connection
05:00.0 Ethernet controller: Intel Corporation 82574L Gigabit Network Connection

The format of EC_T_LINK_PARMS::dwInstance using PCI bus address is:

0x01bbddff

  • bb Bus Number

  • dd Device Number

  • ff Function Number

EC_T_LINK_PARMS::dwInstance = 0x01001900; //"0000:00:19.0"

On Windows the integer value displayed in properties dialog must be converted to HEX. E.g the number from the following dialog (PCI bus 11, device 0, function 0) corresponds to 0x010B0000 (bus 0x0B).