# Modbus RTU - Write an ASCII text with function code 16 into HMI

**URL:** <https://discourse.nodered.org/t/modbus-rtu-write-an-ascii-text-with-function-code-16-into-hmi/12064>\
**Category:** General\
**Created:** [11 June 2019 09:26 UTC](https://discourse.nodered.org/t/modbus-rtu-write-an-ascii-text-with-function-code-16-into-hmi/12064 "2019-06-11T09:26:51Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![iridiu](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/iridiu/32/1213_2.png) [@iridiu](https://discourse.nodered.org/u/iridiu)\
**Post date:** [11 June 2019 09:26 UTC](https://discourse.nodered.org/t/modbus-rtu-write-an-ascii-text-with-function-code-16-into-hmi/12064/1 "2019-06-11T09:26:51Z")

</div>

Hi, I'm trying to write a text to be displayed in a ASCII box in [HMI Modbus RTU device](https://aceautomation.eu/product/hm-070be-hmi-touch-panel-7-0-262144-colors-tft-display-800480-2-serial-ports-2-usb-ports/) with Node-Red Modbus Write and Modbus Flex Write.  
With Modbus Write node I tried to write registers individually with FC3 (register by register) but only the first character is displayed in the text box of the HMI. If I use FC16 to write the full text, I get the error: "Modbus exception 3". The same error is received if I use Modbus Flex Write with this code:

```auto
msg.payload = { value:[65,66,67,68,69,70,71,72,73,74], 
'fc': 16, 
'unitid': 1, 
'address': 90, 
'quantity': 10 } 
return msg

```

I manage to write and read different registers from HMI, but I'm missing something regarding ASCII text box.

 ![Modbus1](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/2X/4/41ede6d61229f5f0a4bf1e824c69fb6727f36eec.jpeg)  
 ![Modbus2](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/2X/7/72aefca1da54b2c6bce156aa76e0e3973e839040.jpeg)

Any help is greatly appreciated