RS232 Splitter

[ivan_ult]

Hi guys, I'm new in the forum, so this is my first post.

I'm trying to connect 2 computer to 1 device (insertion machine communication controller), I've bought a commercial splitter (h t t p://w w w .bb-elec.com/bb-elec/literature/9pmds-3803ds.pdf ), almost everything work fine, but, when I try to download a program to the machine then fail. What I like to try (I think its wrong) is, make a single cable connector, what I mean is take off the diodes and pull down resistors in the diagram.

I appreciate any comment.

Regards

Ivan Sierra Flores

 

[mvs sarma]

Hi guys, I'm new in the forum, so this is my first post.

I'm trying to connect 2 computer to 1 device (insertion machine communication controller), I've bought a commercial splitter (h t t p://w w w .bb-elec.com/bb-elec/literature/9pmds-3803ds.pdf ), almost everything work fine, but, when I try to download a program to the machine then fail. What I like to try (I think its wrong) is, make a single cable connector, what I mean is take off the diodes and pull down resistors in the diagram.

I appreciate any comment.

Regards

Ivan Sierra Flores

Hai Ivan,
Welcome to electro-tech-online

I feel that this is an arrangement that one of the machines can use it at any known time, but both machines cannot simultaneously use. It is perhaps like printer sharer.
the designer meant it for a modem. in a modem, it is one to one communication( straight cable) while working with another local device, I fear Tx of one goes to Rx of another etc, (we may call it crossed cable, if I am right.
please study the set up under this aspect and you would appreciate and perhaps be able to mod it even to suite your needs.

 

[ivan_ult]

Thanks for answer Sarma. What do you think about connect directly the db9 connectors, without components, just the cables

female1 female2 male1
Pin 2 Pin 2 Pin 2
Pin 3 Pin 3 Pin 3
Pin 5 Pin 5 Pin 5

female1 goes to pc1
femal2 goes to pc2
male1 goes to device

I don't need to cross the cables.

Regards

 

[mvs sarma]

Thanks for answer Sarma. What do you think about connect directly the db9 connectors, without components, just the cables

female1 female2 male1
Pin 2 Pin 2 Pin 2
Pin 3 Pin 3 Pin 3
Pin 5 Pin 5 Pin 5

female1 goes to pc1
femal2 goes to pc2
male1 goes to device

I don't need to cross the cables.

Regards

How come you have decided like that?
may I call it NULL Modem Cable and without any active circuit in between
if so on the basis of the link below, i suggest attached schematic.
https://www.lammertbies.nl/comm/cable/RS-232.html#null

 

[ivan_ult]

in the splitter diagram


d1 d2
pc1 pin2 ------------->|----------o-----------|<--------- pc2 pin2
|
|
|
|
| r1
|----------/\/\/\------ gnd (pulldown)
|
|
|
|
o
device pin2


I want to know if I take the components off I can damage one of the pc's or the device.


Thanks