Bar chart label group?

Dashboard
1

the bar chart help is
Multiple series can be shown on the same chart by using a different msg.topic value on each input message. Multiple bars of the same series can be shown by using the msg.label property.

but I try
function1:
msg.topic="series A";
msg.label="bar1";
msg.payload=xxx;

function2:
msg.topic="series A";
msg.label="bar2";
msg.payload=xxx;

function3:
msg.topic="series A";
msg.label="bar3";
msg.payload=xxx;

the bar chart no working, it only dispplay only one bar! why?

2

because you usa the same msg.topic for the 3 values, try to use msg.topic="series A";msg.topic="series B";msg.topic="series C"; and will see....

You answered yourself on the first sentence of the post.

Regards