Network status display for 'ping' results

[Transistor]

From Vince's ping question I have tested the Python script below and it works well.

import os
print '192.168.1.1 ', os.system("ping -n 1 -w 1000 192.168.3.1") == 0

It's running on a Windows host so

• "-n 1" limits it to one ping rather than the default of four
• -w 1000 times it out after 1000 ms in the event of no answer.

Question:
How can I use this to update an indicator status to populate a form with a hundred devices to test?

( ) 10.99.100.1 Good.
(X) 10.99.100.2 No response
( ) 10.99.100.3 Good.
( ) 10.99.100.4 Good.
( ) 10.99.100.5 Good.

Is there a method of incorporating this into a memory or expression tag?

Many thanks.

[JordanCClark]

When I did this, I used two scripts. One was to initialize the contents of a dataset tag with the IP addresses in one column and a ‘Never’ status an the second column. I wrote this, because I have 500-ish IPs to keep track of. More on the status in a moment.

The second script reads the tag holding the IP addresses and statuses, iterates and updates rows whose IPs connect with a time stamp, then writes it back to the tag. This keeps track of the last time that a device was seen.

EDIT: Sorry, I didn’t provide the quite the correct source code for the ‘ping’ script. It had a major flaw that didn’t create the dataset before trying to write to the tag. Edited to reflect correct code.

Initialization script:

# This script initializes a dataset tag so that all results are 'Never'

# tag to hold results
resultsTag = '[default]Ping/Results'

# initialize dataset
headers = ['ip', 'last_ping']
data = []

#list of IP ranges. More than one range can be specified.
ipList = ['192.168.140', '192.168.141']


for ipRange in ipList:
  for i in range(1,255):
    ip_addr = ipRange + '.' + str(i)
    data.append([ip_addr, 'Never'])
dataOut = system.dataset.toDataSet(headers, data)
system.tag.write(resultsTag, dataOut)

‘Ping’ script:

from java.net import InetAddress
from datetime import datetime

resultsTag = '[default]Ping/Results'

dataIn = system.dataset.toPyDataSet(system.tag.read(resultsTag).value)

headers = ['ip', 'last_ping']
data = []


timeout = 200

for row in dataIn:
  ip_addr = row['ip']
  ip = InetAddress.getByName(ip_addr)
  r =  ip.isReachable(timeout)
  if r:
    data.append([row['ip'], str(datetime.now())])
  else:
    data.append(list(row))
  print ip_addr, r
dataOut = system.dataset.toDataSet(headers, data)
system.tag.write(resultsTag, dataOut)

[JordanCClark]

One more thing… Be sure you are running this in a dedicated thread.

If it runs in a shared thread, anything that relies on that thread comes to a screeching halt. While one may ask how I know that, I refuse to answer.

[Transistor]

Thank you, Jordan. That was a great help.
I couldn’t get the Java InetAddress function to work so I replaced it with an os.system call which works fine on my Windows setup.

For anyone else trying this here are a few more detailed steps to get you going.

---

###1. Create the dataset tag
In the Tag Browser create a tag for the dataset tag for the ping results. I created the inside a tag folder called PingTest:

• Name: Results
• Data Type: DataSet
• Enabled: Yes
• Access Rights: Read/Write
• Scan Class: Default

---

###2. Create the gateway event script

In the Project Browser | Project | Scripts double-click Gateway Event Scripts.

####2.1 Startup script code
In the Startup script add the code:

# This script initializes a dataset tag so that all results are 'Never'

# tag to hold results
resultsTag = '[default]PingTest/Results'

# initialize dataset
headers = ['ip', 'last_ping']
data = []

#list of IP ranges. More than one range can be specified.
ipList = ['192.168.0', '192.168.1']

for ipRange in ipList:
  for i in range(200,253): # I'm only interested in addresses above 200.
    ip_addr = ipRange + '.' + str(i)
    data.append([ip_addr, 'Never'])
dataOut = system.dataset.toDataSet(headers, data)
system.tag.write(resultsTag, dataOut)

####2.2 The timer event code
Click the Timer icon | New ‘+’ button.

• Give the timer a name.
• Delay: 30000. (Pings can take a while.)
• Enabled: True.
• Delay Type: Fixed delay
• Threading: Dedicated.

As Jordan has pointed out, you need to set this to “dedicated” thread otherwise all other scripts will pause while this one runs (and many pings can take quite a while).

• Add the code below.

from datetime import datetime
import os

resultsTag = '[default]PingTest/Results'

dataIn = system.dataset.toPyDataSet(system.tag.read(resultsTag).value)

headers = ['ip', 'last_ping']
data = []

for row in dataIn:
  r = os.system("ping -n 1 -w 1000 " + row['ip']) == 0;
  if r:
    data.append([row['ip'], str(datetime.now())])
  else:
    data.append(list(row))
  print row['ip'], r
dataOut = system.dataset.toDataSet(headers, data)
system.tag.write(resultsTag, dataOut)

---

###3. Create the display

• Create a form.
• Add a table.
• Drag and drop the Results tag onto the table.
• Save the project.

The table should update with the results when the last ping is finished.

[albert.bartolome]

Hi, is this ping script applicable to Linux Ubuntu as well?

[JordanCClark]

Yes, it uses Java libraries, so it should be platform independent.

[Transistor]

You may need to modify the os ping call for Linux.

r = os.system("ping -n 1 -w 1000 " + row['ip']) == 0;

to something like

r = os.system("ping -c 1 -w 1000 " + row['ip']) == 0;

It’s ‘-n’ in Windows and ‘-c’ in Linux. Check the manual.

You just want it to try once and then give up.