SN65HVD74: How can a full duplex transceiver be connected to a half-duplex device

The driver of the SN65HVD74 is always enabled. So when you connect its output pins to the bus pins of the ISO1410, the latter will never be able to transmit anything.

You can do this only if you do not connect the SN65HVD74's outputs, i.e., if that node never transmits.

Hi Clemens,

First of all, thanks for the quick reply. However it seems there was a little miscommunication from my side.

What I was asking, if possible, was, to use the SN65HVD74D full duplex transceiver to connect to a MODBUS master. The latter has only two lines for both transmit and receive modes and hence is half-duplex in nature. So I was thinking if there is any configuration in which one could use the SN65HVD74D as a half duplex transceiver effectively.

The purpose of even mentioning ISO1410 is because it is a half-duplex transceiver and I cannot use it right now as we are short on it.

Can you suggest if what I am implying is even possible with SN65HVD74D full duplex transceiver?

Thanks in advance,

-Chandrasekhar DVS

Every half-duplex transceiver works in the same way. The SN65HVD74 output is always active, so no other output on the bus can be active.