# A buffer as payload from function node
**URL:** https://discourse.nodered.org/t/a-buffer-as-payload-from-function-node/94506
**Category:** General
**Tags:** function-node
**Created:** [10 January 2025 10:49 UTC](https://discourse.nodered.org/t/a-buffer-as-payload-from-function-node/94506 "2025-01-10T10:49:42Z")
**Posts on this page:** 6
**Page:** 1
### Author:  [@lbh00](https://discourse.nodered.org/u/lbh00)
#### Post date: [10 January 2025 10:49 UTC](https://discourse.nodered.org/t/a-buffer-as-payload-from-function-node/94506/1 "2025-01-10T10:49:42Z")
Hello,
I have a flow in Node-red in which a function will have to send a binary message to the serial port node.
I set up the function node with code similar to this
```auto
blReply =[217,181,0,75];
for (i=0; i< blReply.length; i++){
msg.payload = blReply[i];
node.send(msg);
}
```
When I receive the data on the serial port , the data received is actually a string (ASCII encoded)
the string received on the other end of the serial port is actually [217,181,0, 75].
I was expecting to receive the binary equivalent of the integers 217 181 0 and 75.
When I inject using the inject node the buffer [217,181,0, 75] the data recieved on the other end of the serial port is as expected the integers 217, 181, 0 and 75.
I Can't see what is wrong in the function node code, can you please help me out with this ?
Regards
lbh00
---
### Author:  [@dceejay](https://discourse.nodered.org/u/dceejay)
#### Post date: [10 January 2025 10:55 UTC](https://discourse.nodered.org/t/a-buffer-as-payload-from-function-node/94506/2 "2025-01-10T10:55:13Z")
do you need to send one character at a time ? Why not just send the array as-is ? ie
```auto
msg.payload = [217,181,0,75];
node.send msg;
```
The serial port should send that as a binary payload.
---
### Author:  [@lbh00](https://discourse.nodered.org/u/lbh00)
#### Post date: [10 January 2025 13:42 UTC](https://discourse.nodered.org/t/a-buffer-as-payload-from-function-node/94506/3 "2025-01-10T13:42:42Z")
Hello Dceejay,
Thanks for your reply.
Well sending 1 byte after the other was one way of debugging to understand what is going on.
I retried your proposal and I still get the data as an ASCII encoded message.
I connected a debug node to snoop on the data transiting from the function node to the serialport node I notice some differences:
the data sent from the function node the msg.payload is typed as array, while the msg.payload injected by the inject node is typed as buffer. What is the difference ?
Regards
lbh00
---
### Author:  [@lbh00](https://discourse.nodered.org/u/lbh00)
#### Post date: [10 January 2025 14:41 UTC](https://discourse.nodered.org/t/a-buffer-as-payload-from-function-node/94506/4 "2025-01-10T14:41:44Z")
Hello,
I looked at the code of serialport node, and apparently if the typeof msg.payload is not a buffer, serial port will convert it to a string. a snip from the serialport node code:
encodePayload:
```auto
function (payload) {
if (!Buffer.isBuffer(payload)) {
if (typeof payload === "object") {
payload = JSON.stringify(payload);
}
else {
payload = payload.toString();
}
if (addchar !== "") { payload += addchar; }
}
else if (addchar !== "") {
payload = Buffer.concat([payload,Buffer.from(addchar)]);
}
return payload;
},
```
so what I did, is convert the array to a buffer inside my function as follows:
```auto
var payload = Buffer.from([217,181,0,75])
```
then send it to serialport node.
I hope this helps someone who is having this issue too.
Regards
lbh00
---
### Author:  [@dceejay](https://discourse.nodered.org/u/dceejay)
#### Post date: [10 January 2025 16:07 UTC](https://discourse.nodered.org/t/a-buffer-as-payload-from-function-node/94506/5 "2025-01-10T16:07:29Z")
Aha - of course... yes - do exactly that.
---
### Author:  [@system](https://discourse.nodered.org/u/system)
#### Post date: [10 April 2025 16:08 UTC](https://discourse.nodered.org/t/a-buffer-as-payload-from-function-node/94506/6 "2025-04-10T16:08:15Z")
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