# Basic queries on "wip\_event" for a TCP-Socket-Channel

**URL:** <https://forum.sierrawireless.com/t/basic-queries-on-wip-event-for-a-tcp-socket-channel/8605>\
**Category:** Open AT\
**Created:** [June 6, 2016, 6:16pm UTC](https://forum.sierrawireless.com/t/basic-queries-on-wip-event-for-a-tcp-socket-channel/8605 "2016-06-06T18:16:07Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![ajaygarg](https://avatars.discourse-cdn.com/v4/letter/a/bc8723/32.png) [@ajaygarg](https://forum.sierrawireless.com/u/ajaygarg)\
**Post date:** [June 6, 2016, 6:16pm UTC](https://forum.sierrawireless.com/t/basic-queries-on-wip-event-for-a-tcp-socket-channel/8605/1 "2016-06-06T18:16:07Z")

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Hi All.

I guess (please correct me wrong) that the WIP\_CEV\_READ event is triggered, when the socket-recv-buffer has received some data from the network. Such kind of event makes perfect sense.

I, however, wonder when/what/how causes the WIP\_CEV\_WRITE event to be triggered.  
The data is written into the socket-send-buffer by the application, which obviously is a synchronous phenomenon.

So, what causes the WIP\_CEV\_WRITE “event”?

Please bear with me, as although I have fair background of systems/socket programming, but I am really an absolute newbie to Sierra-Wireless as of now 🙂

Looking forward to pointers.

Thanks and Regards,  
Ajay

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**Author:** ![Rex\_alex](https://avatars.discourse-cdn.com/v4/letter/r/73ab20/32.png) [@Rex\_alex](https://forum.sierrawireless.com/u/Rex_alex)\
**Post date:** [June 7, 2016, 8:49am UTC](https://forum.sierrawireless.com/t/basic-queries-on-wip-event-for-a-tcp-socket-channel/8605/2 "2016-06-07T08:49:32Z")

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Hi Ajay,  
It’s well explained in the WIP\_Open\_AT\_IP\_Development\_Connectivity guide. you can refer ‘Write Events’ under the section ‘TCPClient: TCP Communication Sockets’

-Alex

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**Author:** ![ajaygarg](https://avatars.discourse-cdn.com/v4/letter/a/bc8723/32.png) [@ajaygarg](https://forum.sierrawireless.com/u/ajaygarg)\
**Post date:** [June 7, 2016, 10:27am UTC](https://forum.sierrawireless.com/t/basic-queries-on-wip-event-for-a-tcp-socket-channel/8605/3 "2016-06-07T10:27:58Z")

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Thanks Rex\_alex,

Exactly what I needed !!! 🙂  
Thanks a ton !!

Thanks and Regards,  
Ajay