# Perspective numeric entry value to plc via modbus

**URL:** <https://forum.inductiveautomation.com/t/perspective-numeric-entry-value-to-plc-via-modbus/36045>\
**Category:** Ignition\
**Created:** [June 25, 2020, 3:58pm UTC](https://forum.inductiveautomation.com/t/perspective-numeric-entry-value-to-plc-via-modbus/36045 "2020-06-25T15:58:55Z")\
**Posts on this page:** 5\
**Page:** 1

<div class="post-metadata">

**Author:** ![dirk1](https://avatars.discourse-cdn.com/v4/letter/d/977dab/32.png) [@dirk1](https://forum.inductiveautomation.com/u/dirk1)\
**Post date:** [June 25, 2020, 3:58pm UTC](https://forum.inductiveautomation.com/t/perspective-numeric-entry-value-to-plc-via-modbus/36045/1 "2020-06-25T15:58:55Z")

</div>

Managed to graduate from kindergarten by creating numeric entry component in Edge Perspective.  
Value reflected in tag.  
Got through first grade by sending double word integer from automationdirect plc via modbus to another Edge tag.  
Stumped in second grade trying to get value from kindergarten project to plc.  
I’ve tried several different value sources, including separate reference tag, and source tag paths with no success.  
Does this require scripting to get value into modbus holding registers or am I missing something obvious?

---

<div class="post-metadata">

**Author:** ![paul-griffith](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/paul-griffith/32/37249_2.png) [@paul-griffith](https://forum.inductiveautomation.com/u/paul-griffith)\
**Post date:** [June 25, 2020, 4:12pm UTC](https://forum.inductiveautomation.com/t/perspective-numeric-entry-value-to-plc-via-modbus/36045/2 "2020-06-25T16:12:38Z")

</div>

Is your numeric entry field’s `value` property binding marked ‘Bidirectional’? It’s a little checkbox in the binding configuration.

---

<div class="post-metadata">

**Author:** ![dirk1](https://avatars.discourse-cdn.com/v4/letter/d/977dab/32.png) [@dirk1](https://forum.inductiveautomation.com/u/dirk1)\
**Post date:** [June 25, 2020, 4:23pm UTC](https://forum.inductiveautomation.com/t/perspective-numeric-entry-value-to-plc-via-modbus/36045/3 "2020-06-25T16:23:18Z")

</div>

Yes, binding is bi-directional. Value entered in numeric entry field is reflected in OPC tag. Now, I’d like to get the value in the tag transmitted to a memory register in the plc via modbus.

---

<div class="post-metadata">

**Author:** ![paul-griffith](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/paul-griffith/32/37249_2.png) [@paul-griffith](https://forum.inductiveautomation.com/u/paul-griffith)\
**Post date:** [June 25, 2020, 5:36pm UTC](https://forum.inductiveautomation.com/t/perspective-numeric-entry-value-to-plc-via-modbus/36045/4 "2020-06-25T17:36:42Z")

</div>

Hmm - have you already brought the holding register you want to write into Ignition as another OPC tag, or are you trying to avoid that?  
If the former, then the easiest option is probably a tag event script using [`system.tag.writeAsync`](https://docs.inductiveautomation.com/display/DOC80/system.tag.writeAsync).

If you don’t want to make a tag in Ignition for the holding register, then you could use [`system.opc.writeValue`](https://docs.inductiveautomation.com/display/DOC80/system.opc.writeValue) to issue a direct write - you’ll still need to have Ignition connected to the Modbus device, but you won’t need to have any actual Ignition tags reading from it.

---

<div class="post-metadata">

**Author:** ![dirk1](https://avatars.discourse-cdn.com/v4/letter/d/977dab/32.png) [@dirk1](https://forum.inductiveautomation.com/u/dirk1)\
**Post date:** [June 25, 2020, 5:50pm UTC](https://forum.inductiveautomation.com/t/perspective-numeric-entry-value-to-plc-via-modbus/36045/5 "2020-06-25T17:50:49Z")

</div>

Thanks much.  
I’ll give these a try.  
Now, if I can only figure out how to keep the big kids from taking my lunch money …