# Ignition 8.1.3: exception caught during sendRequest **URL:** \ **Category:** Ignition\ **Created:** [April 7, 2021, 1:26pm UTC](https://forum.inductiveautomation.com/t/ignition-8-1-3-exception-caught-during-sendrequest/45340 "2021-04-07T13:26:25Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![pgmo](https://avatars.discourse-cdn.com/v4/letter/p/d07c76/32.png) [@pgmo](https://forum.inductiveautomation.com/u/pgmo)\ **Post date:** [April 7, 2021, 1:26pm UTC](https://forum.inductiveautomation.com/t/ignition-8-1-3-exception-caught-during-sendrequest/45340/1 "2021-04-07T13:26:25Z")
I’m using Ignition **8.1.3 (b2021030309)** and an S7-1500 device. I’m experiencing the following issue while trying to write to the PLC with a `system.tag.writeBlocking` instruction: ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/a/a/aa16f93f76c5fbb7482ce628c5c4e6148499a5a6.png) I’ve defined two S7-1500 devices, one for INTs, FLOATs and one for STRINGs (I have some STRINGs which span up to 255 chars): the `writeBlocking` instruction should write at the same time to variables some of which are defined on one device and the remaining on the other device. Any suggestion? ---
**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:** [April 7, 2021, 1:28pm UTC](https://forum.inductiveautomation.com/t/ignition-8-1-3-exception-caught-during-sendrequest/45340/2 "2021-04-07T13:28:00Z")
Does it happen with every invocation of `writeBlocking` with some combination of tags? ---
**Author:** ![pgmo](https://avatars.discourse-cdn.com/v4/letter/p/d07c76/32.png) [@pgmo](https://forum.inductiveautomation.com/u/pgmo)\ **Post date:** [April 7, 2021, 1:52pm UTC](https://forum.inductiveautomation.com/t/ignition-8-1-3-exception-caught-during-sendrequest/45340/3 "2021-04-07T13:52:28Z")
Hallo Kevin, thanks for your help. Yes it does. If I print the `writeBlocking` return array I get such an array of issues: ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/6/3/63db21a1516c227a0e2e301e5592214f96f5e548.png) This occurs independent on the group of tags I try to update in the same `writeBlocking` instruction - I tried to leave the STRINGs variables out of the instruction and it happens all the same. Howevere tags can be written to from the tag browser with no problem. Side note: this morning all was working like a charm! … but nothing changed … ---
**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:** [April 7, 2021, 1:55pm UTC](https://forum.inductiveautomation.com/t/ignition-8-1-3-exception-caught-during-sendrequest/45340/4 "2021-04-07T13:55:36Z")
Hmm, well seems like it’s a bug to me. I would just open a ticket with support. If you can provide the list of tags that triggers this it should be easy to reproduce and fix. ---
**Author:** ![pgmo](https://avatars.discourse-cdn.com/v4/letter/p/d07c76/32.png) [@pgmo](https://forum.inductiveautomation.com/u/pgmo)\ **Post date:** [April 7, 2021, 2:06pm UTC](https://forum.inductiveautomation.com/t/ignition-8-1-3-exception-caught-during-sendrequest/45340/5 "2021-04-07T14:06:31Z")
Hallo Kevin, I’ve tried to post the gateway backup, but the file is too big. However next the code that causes the Excption: ```auto tags=[] values=[] tags.append('[default]GestioneLavorazione/Stazione%d/ActionCode' % (stationNr) ) tags.append('[default]GestioneLavorazione/Stazione%d/iParam1' % (stationNr) ) tags.append('[default]GestioneLavorazione/Stazione%d/iParam2' % (stationNr) ) tags.append('[default]GestioneLavorazione/Stazione%d/iParam3' % (stationNr) ) tags.append('[default]GestioneLavorazione/Stazione%d/fParam1' % (stationNr) ) tags.append('[default]GestioneLavorazione/Stazione%d/fParam2' % (stationNr) ) tags.append('[default]GestioneLavorazione/Stazione%d/fParam3' % (stationNr) ) tags.append('[default]GestioneLavorazione/Stazione%d/sParam1' % (stationNr) ) tags.append('[default]GestioneLavorazione/Stazione%d/sParam2' % (stationNr) ) tags.append('[default]GestioneLavorazione/Stazione%d/sParam3' % (stationNr) ) tags.append('[default]GestioneLavorazione/Stazione%d/HMIlabel' % (stationNr) ) tags.append('[default]GestioneLavorazione/Stazione%d/HMIjpeg' % (stationNr) ) values.append(row['ActionCode'] ) values.append(row['iParam1'] ) values.append(row['iParam2'] ) values.append(row['iParam3'] ) values.append(row['fParam1'] ) values.append(row['fParam2'] ) values.append(row['fParam3'] ) values.append(row['sParam1'] ) values.append(row['sParam2'] ) values.append(row['sParam3'] ) values.append(row['HMIlabel'] ) values.append(row['HMIjpeg'] ) print system.tag.writeBlocking(tags,values) ``` where `row` is a row in a `pyDataset` resulting from a query on the database, `ActionCode` and `iParamX` are integer, `fParamX` are FLOATs, `sParamX` and `HMIlabel` are STRINGs. As noted above, STRINGs are isolated in their own device, but the error occures even if I leave the STRING variables out of the `writeBlocking` instruction. ---
**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:** [April 7, 2021, 2:09pm UTC](https://forum.inductiveautomation.com/t/ignition-8-1-3-exception-caught-during-sendrequest/45340/6 "2021-04-07T14:09:07Z")
If you can add `print tags` and `print values` statements before the `writeBlocking` call it would help to see that output. ---
**Author:** ![pgmo](https://avatars.discourse-cdn.com/v4/letter/p/d07c76/32.png) [@pgmo](https://forum.inductiveautomation.com/u/pgmo)\ **Post date:** [April 7, 2021, 2:20pm UTC](https://forum.inductiveautomation.com/t/ignition-8-1-3-exception-caught-during-sendrequest/45340/7 "2021-04-07T14:20:17Z")
Hallo Kevin, I think I’ve found: the recipe I’m trying to download to the PLC this afternoon has a `NULL` for one of its field which is a `None` for one of the `values` submitted to the `writeBlocking` instruction. That is causing the writing issue for sure. Many thanks for your valuable help! ---
**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:** [April 7, 2021, 3:22pm UTC](https://forum.inductiveautomation.com/t/ignition-8-1-3-exception-caught-during-sendrequest/45340/8 "2021-04-07T15:22:35Z")
Ok. I still think there’s a bug here because the driver should handle receiving a null value better than throwing an NPE.