# SafeDOMAIN-to-SafeDOMAIN - 2x X20SL810x in one configuration **URL:** \ **Category:** How-To & Wikis\ **Tags:** mapp-safety\ **Created:** [November 3, 2025, 3:04pm UTC](https://community.br-automation.com/t/safedomain-to-safedomain-2x-x20sl810x-in-one-configuration/8873 "2025-11-03T15:04:23Z")\ **Posts on this page:** 2\ **Page:** 1
**Author:** ![marek.svozil](https://avatars.discourse-cdn.com/v4/letter/m/FF8800/32.png) [@marek.svozil](https://community.br-automation.com/u/marek.svozil)\ **Post date:** [November 3, 2025, 3:04pm UTC](https://community.br-automation.com/t/safedomain-to-safedomain-2x-x20sl810x-in-one-configuration/8873/1 "2025-11-03T15:04:23Z")
# Motivation : Why would I ever need more than one X20SL810x in a single application? One reason may be the size of the application, and it is advisable to divide the large Safety between 2 X20SL810x and between 2 programmers. There may be several another reasons, but in this case, this solution suited the customer best. The customer needed two “independent” nodes that evaluate safety locally but also communicate with each other and know the status of the other. So they only need to communicate some global statuses. # Example application / Exercise : Let’s take a look at an example where the goal is: If StationA/SafeA has “GREEN” can produce, but if StationB/SafeB has RED then cannot produce, and then the entire Safety have to hold the entire machine and nothing can start. We have two part of machine, SafeA and SafeB, and the entire Safety system is only fulfilled if both SafeA and SafeB are in GREEN state. Let’s consider an example where the goal is to ensure machine safety based on the status of two safety zones: SafeA and SafeB. - If **SafeA** is in the **GREEN** state AND **SafeB** is in the **GREEN** state, then machine is allowed to produce. - If **SafeA** is in the **RED** state OR **SafeB** is in the **RED** state, then production is not allowed. In other words, the machine consists of two safety parts – **SafeA** and **SafeB** – and the overall safety condition is fulfilled only when both are in the GREEN state. If either part is RED/YELLOW, the system must prevent any operation. ## Implementation : If I wanted to have more than one X20SL8100 in a single configuration, this could be achieved using SafeDOMAIN-to-SafeDOMAIN. I create HW configuration with two X20SL810x with two Safe Projects : X20SL8101 - Safe A - SafeDOMAIN 1 , Port 50000 X20SL8100 - Safe B - SafeDOMAIN 2 , Port 50001 ![image-2025-11-3_14-18-18](https://europe1.discourse-cdn.com/brcommunity/original/2X/3/34d5a4e704c74473ac0a0d666b214d0e31a6e552.png) And set Connection from SafeDOMAIN 1 to SafeDOMAIN 2. ![image-2025-11-3_14-17-52](https://europe1.discourse-cdn.com/brcommunity/original/2X/b/ba3dc3b247a80c9588b05532b50a31264ce25ca0.png) Then set IO mapping for Safe A, and Safe B. We try just simple Safe application. ![image-2025-11-3_14-24-13](https://europe1.discourse-cdn.com/brcommunity/original/2X/b/bf5aa49307f89b6bf458e912858281e6712b6e4d.png) And create simple Safe application. In Safe application for SafeA I can also see Inputs/Outpust from SafeB (because we configured SafeDOMAIN-to-SafeDOMAIN). ![image-2025-11-3_14-38-8](https://europe1.discourse-cdn.com/brcommunity/original/2X/1/1bad2f1f223f97f0043c26d55ce9bdd4228d9595.png) ## Test : #### SafeA : Green = 0 , SafeB : Green = 0 ===\> SafeA\_SafeB\_OK = 0 ![image-2025-11-3_15-31-54](https://europe1.discourse-cdn.com/brcommunity/original/2X/f/f7634c9026fe8f3264a7975ba0564958c34cb5c4.png) #### SafeA : Green = 1 , SafeB : Green = 0 ===\> SafeA\_SafeB\_OK = 0 ![image-2025-11-3_15-32-37](https://europe1.discourse-cdn.com/brcommunity/original/2X/3/303f1d121b922d9fa5909ebb7fd0ab5b71a7437b.png) #### SafeA : Green = 1 , SafeB : Green = 1 ===\> SafeA\_SafeB\_OK = 1 ![image-2025-11-3_15-33-36](https://europe1.discourse-cdn.com/brcommunity/original/2X/6/65b5e71dcd244db7f63f151f62ff9ada6069da20.png) ## Project : Passwords : SafeA8101: Development : dddddd Commissioning : cccccc Remote Connection : rrrrrr SafeB8100: Development : dddddd Commissioning : cccccc Remote Connection : rrrrrr [v01\_OK\_Work\_SafeDomain\_to\_SafeDomain.zip](https://community.br-automation.com/uploads/short-url/317pDfPMXT7Tuww5Xi1hUHIdSm.zip) (2.7 MB) ---
**Author:** ![kovarj](https://dub1.discourse-cdn.com/brcommunity/user_avatar/community.br-automation.com/kovarj/32/537_2.png) [@kovarj](https://community.br-automation.com/u/kovarj)\ **Post date:** [November 3, 2025, 6:13pm UTC](https://community.br-automation.com/t/safedomain-to-safedomain-2x-x20sl810x-in-one-configuration/8873/2 "2025-11-03T18:13:19Z")
amazing, thanks @marek.svozil for sharing 🙂