RS485 Transceivers: Will All Receivers See Data Without a Microprocessor?

I want to make sure I am right here:

If I send data down a single RS485 output to a serially connected array of RS485 transceivers, will the data be seen and translated on all receivers?

I am asking because I want a really long clock line to be seen simultaneously on multiple points of a large system that does not need a microprocessor.

from what I can tell, an RS485 receiver will decode all the differential data, and it is up to software to distinguish from data for slave 1, slave 2, etc...

is this right? Do I need to draw an image?

Yes absolutely I think an image would be convenient

here ya go.

I read all about RS485 and used it plenty, but normally with masters/slaves, but this time I simply want a signal to be reproduced a bunch - the SCK clock line. is this a proper?

You don't need a microprocessor. Assuming you hard wire the transmitter correctly (to transmit) and the receivers to receive the clock signal will be appear at the receivers. Luckily you are only transmitting in one direction which simplifies things a little.

Some things to consider:
1. How long is "really long"?
2. What is the maximum clock frequency?
3. You would also have to consider terminating the bus lines depending on the transmission
speed and line length.

Keeping in mind the 32 node limit on RS485 (some newer drivers allow up to 128 nodes, more?), you can add more units (nodes) easily without issues about bus loading and adding bus capacitance.

Hard wiring the drivers will of course increase current consumption, but in comparison with the LEDs this is negligible.

Let us know how it goes...

Long is anywhere within a Venue/amphitheater from the main control center which typically sits behind or on stage.

nothing should be clocked faster than 300khz, but realistic clocking should be around 200,000khz...

Anyhow, I've modified my design to simply include 8 cheap msp430's and only 8 RS485, removing 8 RS485 and subtracting 16 wires from a design that already had 80 wires.

But thanks for verifying that the hardware idea should work, I'll keep it in mind if I ever actually need 8 long data lines of the same data.

The max RS-485 can go is approxamatly 4000 ft at 300khz. You should also consider propagation delay if you are going distances closed to the max. Hopfully the propogation delay doesnt affect all your receivers no receiving the clock signal EXACTLY at the same time. These propogation delays are typically in the micro- seconds.. you should also think about optacally isolated transmitters and receivers. If you dont you can get ground loops and levl shifting that can cause the receivers not to see the transmitter.