# pDevice Slave and Master in LibDRVmbus

**URL:** <https://community.br-automation.com/t/pdevice-slave-and-master-in-libdrvmbus/6921>\
**Category:** B&R Software & Runtime\
**Tags:** modbus\
**Created:** [May 13, 2025, 8:08am UTC](https://community.br-automation.com/t/pdevice-slave-and-master-in-libdrvmbus/6921 "2025-05-13T08:08:03Z")\
**Posts on this page:** 1\
**Showing post:** 2

<div class="post-metadata">

**Author:** ![tommi.piiparinen](https://dub1.discourse-cdn.com/brcommunity/user_avatar/community.br-automation.com/tommi.piiparinen/32/2183_2.png) [@tommi.piiparinen](https://community.br-automation.com/u/tommi.piiparinen)\
**Post date:** [May 13, 2025, 8:42am UTC](https://community.br-automation.com/t/pdevice-slave-and-master-in-libdrvmbus/6921/2 "2025-05-13T08:42:50Z")

</div>

Some different ways to find out the correct pDevice can be found from this post here in the community.

> [@How to find the DeviceName for communication library function blocks (\<Slot\>.\<Subslot\>.\<Interface\>/\<NodeNumber\>/\<ChannelNumber\>)](https://community.br-automation.com/t/how-to-find-the-devicename-for-communication-library-function-blocks-slot-subslot-interface-nodenumber-channelnumber/1249):
>
> When using function blocks such as ArCanSend, a DeviceName input is required to direct the messages to the correct interface. Device Names are given in the following format. \<Slot\>.\<Subslot\>.\<Interface\>/\<NodeNumber\>/\<ChannelNumber\> [image] [https://help.br-automation.com/#/en/4/libraries/arcan/fbks/arcansend.html](https://help.br-automation.com/#/en/4/libraries/arcan/fbks/arcansend.html) This could for example be “SS1.IF1”, which would translate to SubSlot1 Inteface 1. This would be the case when using an X20IF2772 (2 port CAN X20 interface module). [image] If we …

---

_[View the full topic](https://community.br-automation.com/t/pdevice-slave-and-master-in-libdrvmbus/6921)._