# Until I/O input Node inside a Screwdriving Node

**URL:** <https://forum.universal-robots.com/t/until-i-o-input-node-inside-a-screwdriving-node/12880>\
**Category:** URCap Development\
**Created:** [March 11, 2021, 12:50am UTC](https://forum.universal-robots.com/t/until-i-o-input-node-inside-a-screwdriving-node/12880 "2021-03-11T00:50:24Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![joshua](https://avatars.discourse-cdn.com/v4/letter/j/48db29/32.png) [@joshua](https://forum.universal-robots.com/u/joshua)\
**Post date:** [March 11, 2021, 12:50am UTC](https://forum.universal-robots.com/t/until-i-o-input-node-inside-a-screwdriving-node/12880/1 "2021-03-11T00:50:24Z")

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Hello,

I’ve tried searching for this issue but couldn’t find any related topics. When creating a ScrewdriverNode within Polyscope, we typically get an associated Until Node automatically with that node.

In the version of the URCaps SDK I’m using (1.11.0), I can neither access the Screwdriver Node’s Until Node (because of a failed cast from (UntilNode) screwdrivernode.getChildren().get(0) ), nor can I create an Until Node separately and insert it into the Screwdriver Node as a child. Is this a bug? Specifically what I’m trying to do is configure the screwdriver’s until node to have a condition with createDigitalInputConfig(ModbusIO input, boolean valueToProceedUntil)

The error I get specifically is:

ERROR - It is only allowed to insert an Until I/O input node inside a Direction or Waypoint.

Why are screwdriver nodes not allowed to have an Until I/O input Node like the Direction or Waypoint nodes? We can do it in Polyscope, but not through the SDK.

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**Author:** ![sko](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.universal-robots.com/sko/32/573_2.png) [@sko](https://forum.universal-robots.com/u/sko)\
**Post date:** [March 12, 2021, 1:57pm UTC](https://forum.universal-robots.com/t/until-i-o-input-node-inside-a-screwdriving-node/12880/2 "2021-03-12T13:57:52Z")

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Hi Joshua,

despite having the same name/looking the same in the program tree an Until-Node inside the Screwdriver Program node is not the same as an Until-Node inserted via a Direction or Waypoint node. Therefore it is not possible to insert the Until-Node, which is available via the api.

The Screwdriver Until-Node is designed to fit the requirements of the screwdriving process, which does not fit within the needs of the normal program and vice versa.

sko