1. Provisional Hytec Electronic Ltd www.hytec-electronics.co.uk Hytec HotSwap Darrell Nineham Hytec Electronics Ltd

2. Provisional Hytec Electronic Ltd www.hytec-electronics.co.uk Hotswap Hardware Support There is a common misconception that the Hotswap hardware support is limited to the opto switch in the extractor/insertion handles.

3. Provisional Hytec Electronic Ltd www.hytec-electronics.co.uk Other Hotswap Hardware Pre-Charge Voltage (VPC). Pre-leading Pins (PLP) on the VME64x connectors. Electro-Static Discharge.

4. Provisional Hytec Electronic Ltd www.hytec-electronics.co.uk Pre-Charge Voltage (VPC) and Pre-leading Pins (PLP) These PLPs are longer than the other pins on the VME64x connector, allowing them to connect earlier during insertion. This early voltage supply, specifically known as the Pre-Charge Voltage(VPC), is used as a power up the carrier card’s Hot Swap Voltage Controller (SUMMIT IC) and VME Bus buffer IC (Tri-states). The bus is tri-stated actually before its connected, safe guarding the other IOC cards.

5. Provisional Hytec Electronic Ltd www.hytec-electronics.co.uk Electro-Static Discharge The carrier cards have a bottom PCB edge is exposed metal (known as a ‘printed wiring strip’). The carrier card front panel has guide pins both top and bottom to provide additional discharge sources through the guide pin sockets in the IOC. The carrier cards are fitted with 2.2 MegOhms discharge resistors to provide safe discharge paths via any of the above drain sources. This safely discharges the carrier card during any hot swap.

6. Provisional Hytec Electronic Ltd www.hytec-electronics.co.uk Software Support Hytec (particularly Walter Scott, Dave Brownless and Steve Hunt) choose NOT to implement hotswap as specified by Andrew Johnson. They have instead modified his drvpac adding a function ipmCarrierIsPresent().