Setting the Current Melting Level Without Restarting IRIS

Normally, when you change the Setup files, you have to quit and start IRIS to have the changes valid.

For SRI this is not practical, since in the case of fast moving front you might want to update the melting layer height every hour.

To make changes to setups while IRIS is running, you must push information through a pipe to a program called setup_change.

Open a terminal window and type the following command:
```
$ echo "iris_setup.misc.ifallspd_melts[1]=20" | setup_change -load
```
This changes the February melting level to 2.0 km (1.2 mi). Note the number of the month is UNIX style table index, thus 0 is January, 1 is February and similar. The units are in 1/10 of km. You can change many of the profile and melting level setups on the fly.
To make several changes at the same time, put the data in a file as follows:
```
$ echo "iris_setup.misc.ifallspd_melts[1]=20" >testfile
$ echo "iris_setup.misc.ifallspd_melts[2]=25" >>testfile
$ cat testfile | setup_change -load
```
Alternatively, put several name=value pairs in the same string if separated with "\n". You can ssh this string from a central computer to all your various radars. This interface is primarily intended to be invoked from automated script files. To see the current values type the following:
```
$ setup_change -list | grep ifallspd
```
To specify that the melting level is unknown, you set this value to valid in Setup:
```
"iris_setup.misc.lMeltHeightValid = 1"
```
If you stop providing this information, you must set this value to invalid.