---
title: "WIZ1000 send data to RS232, but cannot receive nothing"
url: "https://maker.wiznet.io/forum/12349"
markdown_url: "https://maker.wiznet.io/forum/12349/md"
type: "Forum topic"
category: "General"
author: "Zeljko Hrvoj"
created: "2017-06-28T10:33:48+09:00"
last_activity: "2017-06-29T06:44:52+09:00"
language: "en"
views: 1788
replies: 2
source: "WIZnet Makers forum (https://maker.wiznet.io/forum/)"
---

# WIZ1000 send data to RS232, but cannot receive nothing

## Question

Asked by Zeljko Hrvoj on 2017-06-28 in General.

Hi…

I configured it and tested in TCP Client / TCP server / UDP mode using Hercules.
Now I have it in the Mixed mode.

## 1.) Serial parameters are 115200 E71 - conn to PLC.

Client mode:
I connect to w1000 ip address:5000 and I can send data to PLC and it received it.PLC surely answers but I don’t see this data in client window.

Server mode:
I started server on laptop port 5001. This is entered also to config tool. I can send data to device, but I don’t see the reply.

## 2.) Same serial parameters - serial terminal instead of PLC:

If I connect RS232 terminal instead of PLC, same baud rate, then I see the data I sent from ethernet TCP client via w1000 to RS232.
Also if I type answer to RS232 terminal, now I see those data on my TCP client window!
Why don’t I see them when PLC anwers? Timing??? PLC answers very quick!

For server mode:
Using serial terminal instead of device I see that in server mode RS232 device must establish connection via w1000 to the external TCP server first. After connection is made, then I can send data. Problem is that my PLC doesn’t send nothing first!

For client mode:
I should see the data, because I established contact from PC client first.

Can You help? Firmware 1.6. Any new firmware?
192.168.1.198 iz w1000
192.168.1.23 is my laptop with Hercules

[![](https://maker.wiznet.io/forum_uploads/wiznet/original/2X/2/26ce24f5869802e9463e399ff783f83a56dfabd1.png) 663×626 71.8 KB](https://maker.wiznet.io/forum_uploads/wiznet/original/2X/2/26ce24f5869802e9463e399ff783f83a56dfabd1.png)

## Replies

### Reply 1 by Zeljko Hrvoj, 2017-06-28

Solved.
WiZ1000 doesn’t control handshake lines on RS232 connector. And my PLC doesn’t respond back if DTR is not asserted - positive.

What I can measure is that from handshake signals only pin 7 - RTS is active on WIZ1000, and it is always negative voltage. DTR pin 4 is always 0V which means not connected.

I tried WizVSP (connect serial port to remote host - client) to force signal lines and it doesn’t help even if I change the settings on Signal lines tab. My RTS is always low, and DTR is not connected - it’s 0V.

I use external DC voltage to assert DTR high to PLC, so now PLC answers.

### Reply 2 by irina, 2017-06-29 (in reply to reply 1)

![](https://avatars.discourse-cdn.com/v4/letter/z/cdc98d/48.png) Zeljko_Hrvoj:

> so now PLC answers.

Great! ![:slight_smile:](https://emoji.discourse-cdn.com/twitter/slight_smile.png?v=12)

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Source: https://maker.wiznet.io/forum/12349