# Serial WriteBytes

**URL:** <https://forum.inductiveautomation.com/t/serial-writebytes/12501>\
**Category:** Ignition\
**Created:** [December 28, 2016, 2:48pm UTC](https://forum.inductiveautomation.com/t/serial-writebytes/12501 "2016-12-28T14:48:25Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Polynomial](https://avatars.discourse-cdn.com/v4/letter/p/848f3c/32.png) [@Polynomial](https://forum.inductiveautomation.com/u/Polynomial)\
**Post date:** [December 28, 2016, 2:48pm UTC](https://forum.inductiveautomation.com/t/serial-writebytes/12501/1 "2016-12-28T14:48:25Z")

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Hello,

I’m trying to send the following hex values to a serial device using the system.serial.writeBytes() function: \x01\x01\x00\x00\x00\x0A\xBC\x0D

Can anyone assist me with how to convert that line of hex into the java.lang byte[] that Ignition is looking for? I’m been struggling with this all morning.

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<div class="post-metadata">

**Author:** ![Polynomial](https://avatars.discourse-cdn.com/v4/letter/p/848f3c/32.png) [@Polynomial](https://forum.inductiveautomation.com/u/Polynomial)\
**Post date:** [December 28, 2016, 4:51pm UTC](https://forum.inductiveautomation.com/t/serial-writebytes/12501/2 "2016-12-28T16:51:50Z")

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I discovered after reading many forum posts that once the serial module is installed a Modbus RTU (over serial link) device appears in the selection list when adding a device to OPC-UA.

Once I configured my device I was able to create tags as usual using modbus addresses.