# Error when executing a timer script

**URL:** <https://forum.inductiveautomation.com/t/error-when-executing-a-timer-script/43564>\
**Category:** Ignition\
**Created:** [February 18, 2021, 1:18pm UTC](https://forum.inductiveautomation.com/t/error-when-executing-a-timer-script/43564 "2021-02-18T13:18:45Z")\
**Posts on this page:** 5\
**Page:** 1

<div class="post-metadata">

**Author:** ![lachguerabdallah](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/lachguerabdallah/32/25558_2.png) [@lachguerabdallah](https://forum.inductiveautomation.com/u/lachguerabdallah)\
**Post date:** [February 18, 2021, 1:18pm UTC](https://forum.inductiveautomation.com/t/error-when-executing-a-timer-script/43564/1 "2021-02-18T13:18:45Z")

</div>

Ignition 8.0.12

I have a project function. I call this function from a timer script. but i get an error on the gateway.

the function works fine when I call it from somewhere in the project.

please help

the error is the following:

```auto
com.inductiveautomation.ignition.common.script.JythonExecException: Traceback (most recent call last): File "", line 27, in checkValues at java.base/java.util.concurrent.CompletableFuture.timedGet(Unknown Source) at java.base/java.util.concurrent.CompletableFuture.get(Unknown Source) at com.inductiveautomation.ignition.gateway.script.LegacyGatewayTagUtilities.read(LegacyGatewayTagUtilities.java:459) at com.inductiveautomation.ignition.common.script.builtin.LegacyTagUtilities.read(LegacyTagUtilities.java:168) at jdk.internal.reflect.GeneratedMethodAccessor13.invoke(Unknown Source) at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) at java.base/java.lang.reflect.Method.invoke(Unknown Source) java.util.concurrent.TimeoutException: java.util.concurrent.TimeoutException

at org.python.core.Py.JavaError(Py.java:552)

at org.python.core.Py.JavaError(Py.java:543)

at org.python.core.PyReflectedFunction. __call__ (PyReflectedFunction.java:190)

at com.inductiveautomation.ignition.common.script.ScriptManager$ReflectedInstanceFunction. __call__ (ScriptManager.java:521)

at org.python.core.PyObject. __call__ (PyObject.java:480)

at org.python.core.PyObject. __call__ (PyObject.java:484)

at org.python.pycode._pyx2262.checkValues$2(:35)

at org.python.pycode._pyx2262.call_function()

at org.python.core.PyTableCode.call(PyTableCode.java:171)

at org.python.core.PyBaseCode.call(PyBaseCode.java:308)

at org.python.core.PyFunction.function ___call__ (PyFunction.java:471)

at org.python.core.PyFunction. __call__ (PyFunction.java:466)

at org.python.core.PyFunction. __call__ (PyFunction.java:456)

at org.python.core.PyFunction. __call__ (PyFunction.java:451)

at com.inductiveautomation.ignition.common.script.ScriptManager.runFunction(ScriptManager.java:815)

at com.inductiveautomation.ignition.gateway.project.ProjectScriptLifecycle$TrackingProjectScriptManager.runFunction(ProjectScriptLifecycle.java:687)

at com.inductiveautomation.ignition.gateway.script.GatewayTagUtilities.lambda$readAsyncImpl$1(GatewayTagUtilities.java:138)

at java.base/java.util.concurrent.CompletableFuture.uniWhenComplete(Unknown Source)

at java.base/java.util.concurrent.CompletableFuture$UniWhenComplete.tryFire(Unknown Source)

at java.base/java.util.concurrent.CompletableFuture.postComplete(Unknown Source)

at java.base/java.util.concurrent.CompletableFuture$AsyncSupply.run(Unknown Source)

at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)

at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)

at java.base/java.lang.Thread.run(Unknown Source)

Caused by: org.python.core.PyException: Traceback (most recent call last): File "", line 27, in checkValues at java.base/java.util.concurrent.CompletableFuture.timedGet(Unknown Source) at java.base/java.util.concurrent.CompletableFuture.get(Unknown Source) at com.inductiveautomation.ignition.gateway.script.LegacyGatewayTagUtilities.read(LegacyGatewayTagUtilities.java:459) at com.inductiveautomation.ignition.common.script.builtin.LegacyTagUtilities.read(LegacyTagUtilities.java:168) at jdk.internal.reflect.GeneratedMethodAccessor13.invoke(Unknown Source) at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) at java.base/java.lang.reflect.Method.invoke(Unknown Source) java.util.concurrent.TimeoutException: java.util.concurrent.TimeoutException

... 24 common frames omitted

Caused by: java.util.concurrent.TimeoutException: null

at java.base/java.util.concurrent.CompletableFuture.timedGet(Unknown Source)

at java.base/java.util.concurrent.CompletableFuture.get(Unknown Source)

at com.inductiveautomation.ignition.gateway.script.LegacyGatewayTagUtilities.read(LegacyGatewayTagUtilities.java:459)

at com.inductiveautomation.ignition.common.script.builtin.LegacyTagUtilities.read(LegacyTagUtilities.java:168)

at jdk.internal.reflect.GeneratedMethodAccessor13.invoke(Unknown Source)

at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)

at java.base/java.lang.reflect.Method.invoke(Unknown Source)

at org.python.core.PyReflectedFunction. __call__ (PyReflectedFunction.java:188)

... 21 common frames omitted

```

the function:

````auto
def activePowerCalc():
	
	
	def checkValues(asyncReturn):
		total=0
		i=0
		lista=[]
		label=[]
		value=[]
		
		for qv in asyncReturn:
			lista.append([qv.value,paths[i]])
			total+=qv.value
			i=i+1
		
		listaSorted=sorted(lista, reverse=True)
		
		listaSorted=listaSorted[0:5]
		
		for i in listaSorted:
			stationCode=i[1][5:8]
			stationNamePath='[BB2]'+stationCode+'/_'+stationCode+'/Description'
			stationName=system.tag.read(stationNamePath).value
			label.append(stationName)
			value.append(i[0])
		
		hdr = ['Label','Value']
		fullDS = zip(label,value)
	
		data=system.dataset.toDataSet(hdr,fullDS)	
		system.tag.write('[BB2]_Dashboard/_power',data)
	
				
		
	paths=[
		"[BB2]D01/ST01/PM_0001/PR2/MPPT",
		"[BB2]D02/ST01/PM_0001/PR2/MPPT",
		"[BB2]D03/ST01/PM_0001/PR2/MPPT",
		"[BB2]D04/ST01/PM_0001/PR2/MPPT",
		"[BB2]D05/ST01/PM_0001/PR2/MPPT",
		"[BB2]D09/ST01/PM_0001/PR2/MPPT",
		"[BB2]D10/ST01/PM_0001/PR2/MPPT",
		"[BB2]D13/ST01/PM_0001/PR2/MPPT",
		"[BB2]D14/ST01/PM_0001/PR2/MPPT",
		]
		
		
	
	system.tag.readAsync(paths, checkValues)```
````

---

<div class="post-metadata">

**Author:** ![Kevin.Herron](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/kevin.herron/32/7259_2.png) [@Kevin.Herron](https://forum.inductiveautomation.com/u/Kevin.Herron)\
**Post date:** [February 18, 2021, 1:21pm UTC](https://forum.inductiveautomation.com/t/error-when-executing-a-timer-script/43564/2 "2021-02-18T13:21:44Z")

</div>

I’m not sure if this is the underlying cause or not, but doing an async call in a timer script like this is very dangerous.

What can and likely will happen is that your timer script will execute at a faster rate than some or all of the readAsync calls take to complete and you end up with multiple outstanding async calls stacked up on top of each other.

You should rewrite this to be blocking and see if the issue still occurs.

---

<div class="post-metadata">

**Author:** ![lachguerabdallah](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/lachguerabdallah/32/25558_2.png) [@lachguerabdallah](https://forum.inductiveautomation.com/u/lachguerabdallah)\
**Post date:** [February 18, 2021, 1:25pm UTC](https://forum.inductiveautomation.com/t/error-when-executing-a-timer-script/43564/3 "2021-02-18T13:25:46Z")

</div>

thanks for the reply Kevin.

I have to try using readBlocking instead readAsync ?

---

<div class="post-metadata">

**Author:** ![Kevin.Herron](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/kevin.herron/32/7259_2.png) [@Kevin.Herron](https://forum.inductiveautomation.com/u/Kevin.Herron)\
**Post date:** [February 18, 2021, 1:28pm UTC](https://forum.inductiveautomation.com/t/error-when-executing-a-timer-script/43564/4 "2021-02-18T13:28:47Z")

</div>

> [@lachguerabdallah](#):
>
> I have to try using readBlocking instead readAsync ?

Yes, use `readBlocking` and there won't be any need for the `checkValues` callback function, all of that logic just moves to the lines after the `readBlocking` call gives you the results.

---

<div class="post-metadata">

**Author:** ![lachguerabdallah](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/lachguerabdallah/32/25558_2.png) [@lachguerabdallah](https://forum.inductiveautomation.com/u/lachguerabdallah)\
**Post date:** [February 18, 2021, 1:33pm UTC](https://forum.inductiveautomation.com/t/error-when-executing-a-timer-script/43564/5 "2021-02-18T13:33:15Z")

</div>

thanks you Kevin, now it seems to work perfectly