"Rig-Link"

"Rig-Link" Long-distance step/direction plus enable, using 75-ohm bnc pair

For situations where it's desirable to have the motor drivers on the moco rig, the Rig-Link provides a means of making the logic connection using a pair of inexpensive and easily obtainable 75-ohm bnc cables for a run of up to 200 feet. When used with a Kuper system, the Rig-Link can also control the motor enable function on driver boxes which have that feature. Your bloop light can be sent over the Rig-Link as well, so the bloop can stay with the camera. Three additional lines are available for you to wire your own functions such as lighting effects or even serial communications.

Internal Connections to the Sender:

The sender card lives on the Kuper's ISA bus. At the extreme left end is the ribbon header where you plug in the step/dir ribbon from the Kuper card. If the sender card in plugged into the bus so that it is in front of the Kuper card (looking at the component sides) then you can make a very neat connection between the two cards with a single right-angle fold of the ribbon.

There is a second ribbon header on the sender which is a buffered feed-through of all 16 channels, which you can ribbon out to a female DB37 in the event that you want to have some channels of this group on the rig, and some others on drivers local to the Kuper.

In the lower right-hand third of the card there's a little red two-pin header where you can connect the bloop signal from the 26-pin ribbon header on the Kuper card, which should be "Y"-d out from the 25-pin "RTMC Logic" connector. One good technique is to make a new RTMC-Logic ribbon, with extra ribbon sticking out beyond the connector at one end. Trim off all leads but the bloop (and maybe ground, but this is not necessary) and wire the bloop to the plug at the sender board. "+" is signal, "-" is ground.

External Sender Connections:

Both BNC's must be connected. Observe that one has a splotch of red paint. (There's a similar splotch at the receiver end.) Red goes to red. The bnc cables should be of the same length and type as one another.

The female DB9 is an optional relay for three lines of digital data. These three lines come out at a DB9 male on the receiver box. The signal pins are 3, 4 and 7. Ground is on 5. With this pinout you have the option of using the DB9 to send serial RS-232 data through the Rig-Link, perhaps for a smart slate or camera control. The sender's DB9 will accept RS-232-level signals (or TTL), so you can just run a standard male-female cable to the computer's COM port. The output at the receiver, however, is TTL-level. TTL level works for some, but not all, RS-232 devices.

Connections to the receiver:

Both bnc serial lines must be connected. Observe that the bnc with the red splotch connects to the similarly marked bnc on the sender.

The DB37 has the standard Kuper pinout, except that there are no motor channels above channel 12. Electrically, the signals are the same as they are coming out of Kuper, so they can interface to the same driver circuitry.

1	ground	20	+5 volts
2	step 0	21	dir 0
3	step 1	22	dir 1
4	step 2	23	dir 2
5	step 3	24	dir 3
6	step 4	25	dir 4
7	step 5	26	dir 5
8	step 6	27	dir 6
9	step 7	28	dir 7
10	step 8	29	dir 8
11	step 9	30	dir 9
12	step 10	31	dir 10
13	step 11	32	dir 11
14*	n.c. or enable 0	33*	n.c. or enable 1
15*	n.c. or enable 2	34*	n.c. or enable 3
16*	n.c. or enable 4	35*	n.c. or enable 5
17*	n.c. or enable 6	36*	n.c. or enable 7
18	ground	37	+5 volts
19	ground

* Certain customers have had enable signals brought to these pins as a custom modification. Standard product has no connections to these pins.

DB25 driver enable connector:

Electrically, these signals are the same as the driver signals, i.e., open-collector 30ma capacity, so they drive the low (cathode) side of optoisolators.

DB25 pinout:

1	+5 volts	14	enable 0
2	+5 volts	15	enable 1
3	+5 volts	16	enable 2
4	+5 volts	17	enable 3
5	+5 volts	18	enable 4
6	+5 volts	19	enable 5
7	+5 volts	20	enable 6
8	+5 volts	21	enable 7
9	+5 volts	22	enable 8
10	+5 volts	23	enable 9
11	+5 volts	24	enable 10
12	+5 volts	25	enable 11
13	nc

DB9 user bits:

Bits are TTL, and come out on pins 3, 4 and 7. Pin 5 is ground.

Bloop:

4-pin XLR. Pin 1 is ground, pin 3 is open-collector bloop signal (active-low), pin 4 is +12 volts.

The System in Use:

Drive compatibility: Certain models of stepper drivers are sensitive to the phase-shifting effect which inevitably results from serializing the data. Depending on which drivers you are using, you may need to widen the step pulses from Kuper, through either the "mr" command or the "PWIDTH" pragma. Drivers known to be sensitive to the phase-shifting are:

Lynx IVE microstep drive
Pacific Scientific 5630 above 325,000 pulses/sec

Error lockout: In the event of an interruption, or corruption of the serial signal, the receiver box will shut down and the red light on the front will come on. This is to prevent a rig run-away in the event of a cable pull-out. Push the button to reset the box. If the computer was not powered up first, you will need to reset the box once it is.

Remote Enable:

The drivers are enabled or disabled by clicking on the channel number to the left of the screen. To enable this feature, you must have the "HARDENAB" pragma in the Kuper directory. You need to be aware of whether your drivers are wired as remote-enable or remote-disable. For example, for a system with four remote-enable drivers and eight remote-disable drivers, the pragma file must contain the string of 1's and 0's to set the polarities. The first line in the file would contain the string: 000011111111. WARNING: Current versions of Kuper now in use will allow you to move the axes even if the drives are disabled. As of this writing, Kuper is looking at writing an option for disabling axes whose drives are disabled.

Rig-Link Technology:

The question has often been asked whether one bnc cable is step and the other direction. This is not the case. The two lines together make a differential pair. Both carry the same information, but at inverse polarity to one another. This is more robust for preserving signal integrity than a single line referenced to ground. AMD calls the serial signal "pseudo-ECL." The voltage swings are <1 volt, providing low switching times and reduced noise.

"Daylight Bloop" High-brightness bloop light with bleep, remote trigger, and universal interface

4-pin XLR pinout: 1=ground, 2=trigger, 3=bloop, 4= +5 to 30 volts dc. Bloop signal is ttl, selectable active high or active low.

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Contact John Higbie

"Rig-Link"

Download pdf (1.5 megs)

****Contact John Higbie****

"Rig-Link"

Contact John Higbie