VSDEPI and EXT_RELAY problems

[stevespo]

I am trying to use the EXT_RELAY to enable/disable my spindle, using the 24V (@ 30ma) signal that is provided by my Hitachi X200. I had this working great with my old BOB, but no luck so far with the VSDEPI. I thought I had tested the relay before before, but it's no longer working.

• I'm quite certain my Mach settings are correct. Pin 17 is associated with output 1, which is associated with the spindle on/off.
• I have verified that pin 17 goes to 4.3V when I enable the spindle using the Mach control panel.
• The problem is that the relay does not appear to close to switch the Hitachi into the "on" state.
• There is no audible "click" or change in continuity when I do this (relay state is open).
• (Oddly enough the Hitachi complains about an E13, which is "power applied while run signal is present.")

I'm using the standard RELAY on pin 16 with no problems to switch my small vacuum pump on/off, so I'm familiar with how these things operate. Perhaps I'll try and use that for spindle control for the time being.

The documentation says that EXT_RELAY: "External relay output." 5 Volt relay coils of external relay can be connected to this connector."

Is 24V incorrect for this relay? It appears to be marked 10A/240VAC & 10A/30VDC on the EXT_RELAY side as well as 10A/250VAC/30VDC on the RELAY side. I'm having no luck finding a datasheet for this component, so any help would be greatly appreciated.

Steve

[Al_The_Man]

If I am reading this right it sounds like you are trying to energize a relay from the parallel port?
In any event, the simplest way to go from a parallel port to say a 24vdc relay if needed, would be use a 2N7000 FET interface TTL to a max of 60vdc.
No other component required apart from a reverse diode across the coil.
Spindle relay problems
Al.

[Jason3]

Hey Steve,

Do you have an external relay connected to the EXT_RELAY output?

Best regards,

Jason

Ps - sorry to be obscure, you're using the onboard relay for your vacuum pump? Do you have another relay connected to the EXT-RELAY output, or are you connecting that 5v output directly to your VFD - that would likely cause an error, as the VFD will usually need the 24v circuit closed with the 'enable' pin to start.

I was just wondering if you had thought pin 17 was activating the onboard relay? I might have misread your question, but it sounded as though you were expecting the onboard relay to activate (it should when pin 16 goes high, and as you said, your vacuum pump works). Pin 17 I think just sends ~5v to an external relay, or I guess if your VFD would accept a 5v signal then you could use that to turn on the spindle, but not to close the 24v circuit to enable the spindle. Does that make sense? My brain is a bit fuzzy today, so I'm sorry if that's way off base!

[stevespo]

Yeah, I apologize - my description wasn't all that clear.

I expected the EXT_RELAY (activated by pin 17) to act like a relay, but I guess it might just be supplying +5V to a second relay. It looked like it had an input and output and I thought it was a relay. I should check to see if it is providing +5V. I tried sending +24VDC to it and it may not be functioning properly as a result.

The actual RELAY (activated by pin 16) works the way I expected it to. I can use it to switch a 120VAC signal on/off to control my vacuum pump *or* I can use it to switch the 24VDC@30ma signal from my Hitachi on/off in order to control the spindle. I have verified that this works, so I can use Mach for the spindle and I can control my pump manually for the time being.

So, on the off chance that I have not damaged that EXT_RELAY component, I should be able to use it to turn another solid-state/mechanical relay on/off and use that to control the spindle. I can give that a try.

Steve

[Jason3]

Xerxes might know what the chances are that the output is damaged. If it is, let me know & I can replace your VSDEPI.

Best regards,

Jason

[stevespo]

Xerxes might know what the chances are that the output is damaged. If it is, let me know & I can replace your VSDEPI.

Best regards,

Jason

Much appreciated, but that would be a definite case of "user error" and I'll take full responsibility.

Steve

[Xerxes]

EXT_RELAY works for relay with 5V coils, not 24V. Connecting only 24V relay won't damage (but it breaks if some external power is also fed into it).

One can test EXT_RELAY by putting DC voltimeter on its terminal and changing relay status from PC. Voltage readings should be near 0 when off and 4...5V when on.

[stevespo]

Here's what I am seeing with the EXT_RELAY.

The (innermost, 20) terminal reads a constant +5.1VDC. I believe this is expected behavior.

The (outermost, 10) terminal reads approximately +0.48VDC when pin 17 is low, and a very steady +0.61VDC when pin 17 is high. So, it is responding to the signals from Mach, but not providing the voltage it is supposed to.

As I mentioned above, I did apply 24VDC@30ma to one terminal (probably terminal 10) believing that this was an actual low-voltage relay and not just a relay voltage source.

Short of replacing the board, is there anything that can be done to fix this?

Steve

[Xerxes]

It may be necessary to insert some load to EXT_RELAY to make voltages swing full range (try connecting the relay coil to it and measure again).

If there is damaged components, its probably the ULN2003 chip (available from many places). Please see attached full schematics of VSDEPI for reference.