Can 2 different BMXDDO1602 Module outputs still be directly paralleled together if their respective cards are on different drops (without diodes)?

[maks.chayun]

Say I wanted to implement a redundant I/O scheme where I paralleled two different BMXDDO1602 card outputs whose cards were located on two separate I/O drops (obviously on two different racks).

Assuming:
1) Their pre-actuator terminals were fed from the same power supply.

2) Both outputs are meant both be on or off simultaneously (no mixed states).

Could the outputs be paralleled together directly or would the output first have to go to two different diodes with their cathodes connected together?

I've read on the data sheet for the BMXDDO1602 that their outputs are parallelable (up to two), but I'm not sure if that was referring to outputs that were on the same card or not.

[dnordenberg1]

99% sure it would not matter if it would be from another card. If you are unsure, take something like 1kohm resistor between an enabled output and a disabled and check the current. If the current is like 100 microamps or below then you are fine, it will not cause any harm to parallel the outputs, if it is towards 20mA it is shorting, then turn off.

[GabrieleMicheli]

I suggest you take a look at these files, they are very interesting 🙂

[ProfHameedi]

If you look closely at the schematic circuit of the BMXDDO1602 module, you will see that the output terminals are the DRAIN pins of MOSFET transistors, so connecting (2) output pins together will not affect the internal circuit, especially the GATE circuits are different.

On the contrary, this scheme will enhance the operation and performance by Load Current sharing (Load Current will be divided by 2 pass through 2 transistors).

[YONGHO-KIM]

There is a case where BMXDDO1602 was implemented in duplicate as shown in the pictures above, and applied to the site, please refer to the picture.

[Ricard]

Hello @maks.chayun 

There are options to achieve this redundancy of inputs and outputs through Telefast.

Digital output signals are connected through an ABE7 connection block and multiplexed by a Telefast ABE7ACC10 connection device, a splitter sub-base for output redundancy:

This passive connection sub-base does not require a power supply. In the following example of a 32 DO card, use two 16-channel ABE7ACC10 splitter sub-bases to connect our 32-channel pair of BMXDDO3202 output modules:

Recommended cable BMX FCC xx3

For Digital input signals are connected through an ABE7 connection block. These signals are multiplexed by a Telefast ABE7 ACC11 connection device, which is a splitter sub-base for input redundancy.

This passive connection sub-base does not require a power supply. Our simple example uses
two 16-channel ABE7ACC11 splitter sub-bases to connect the 32-channel pair of BMXDDI3202
input modules:

I'm attaching the link of the catalog of "Telefast Pre-wired system. Modicon ABE7 IP20 connection sub-bases. Modicon ABE9 IP67 passive splitter boxes"

https://www.se.com/es/es/download/document/DIA3ED2160602EN/

Good luck

Ricard