vfs.file.contents returns ZBX_NOTSUPPORTED

[pdube]

I am running Zabbix 2.4.2 and I wish to read a file on a Windows server that contains a float number (that I regenerate every 30 minutes).

The Zabbix item is defined like:
Type: Zabbix Agent
Key: vfs.file.contents[C:\TimeDrift.txt]
Type of information: Numeric (float)
Units: seconds

And I have a trigger on server DC1 that check {DC1:vfs.file.contents[C:\TimeDrift.txt].last()}>120

Here is what I see in the Zabbix log file:
3184:20180405:145536.087 Requested [vfs.file.contents[C:\TimeDrift.txt]]
3184:20180405:145536.087 Sending back [ZBX_NOTSUPPORTED]

File permissions are Everyone: Read on this file.

From the help file I see that vfs.file.contents is available on Windows.

What am I missing?

[BP_Vital]

Hello,
vfs.file.contents returns text, not an integer.
Item Type of information is incorrect, therefore item becomes not supported.

[pdube]

Is there a way I can have Zabbix read an integer/float value from a file then?

[pdube]

Found the solution.

I just need to use a User Parameter (defined in zabbix_agentd.conf) like
UserParameter=TimeDrift,type C:\TimeDrift.txt

and define an Zabbix Item using this parameter.