VMIVME-3122 Single Ended Input


The following questions assume you have a VMIVME-3122 revision 01 board. Check the back side of the board near the P1 connector. You should find the following Assembly part number: 332-013122-xx1. This board is configured with 96pin non-latching connectors for P3 and P4. 

1. What is Jumper J3 on VMIVME-3122-101? Page 45 of the product manual  says "If 96-wire 0.033-inch ribbon cables or discrete wire type cables are used for the analog inputs, the center row can provide a ground reference to the analog return (AGND) on the board by installing Jumper J3."

Reference to J3 on page 45 of the Product Manual (500-003122-000J) is an error. This function is performed by jumpers E1 and E2. There are no "J" jumpers in this product. We apologize for this documentation error.

2. Using discrete wire cables input into P4 of VME3122. The source has 32 HIGH Channels and 16 COM (Analog Return Channels) for Single Ended inputs.

Why are there only 16 return channels? Are some of the channel returns combined at the source? Make sure all 32 High inputs have a corresponding common that is connected to the 3122. Ideally, all 32 common returns would be connected to row B at the 3122 input connector. This will minimize effects of system noise.

3. 32 HIGH input channels will go to P4-RowA (pins 1-32) and 16 COM input channels will go to any P4-Row B pins and P4-Row C will not be used. If this is the case are we still utilizing the 10HZ input Filter that connects from HIGH channel to LOW channel? Does E1 need to be jumpered for the single ended input?

The input filter is still used, but the corner frequency will be increased to 20Hz due to the single-ended configuration which effectively reduces the filter input resistance to half its value. The purpose of jumpers E1 and E2 are to provide access to analog ground for 64 conductor cables that only use the A and C rows. Since you will be connecting your common returns directly to the B row, the E1 and E2 jumpers do not need to be installed.