Related Products: DA Module Family (DA1, DA2, DA3, DA4, DA5), CME, CMF
Overcurrent Latched on Startup
When power is first applied to our VME chassis where the NAI Multifunction I/O Board resides, the D/A module sometimes gets in a latched overcurrent condition. There is nothing connected to the D/A outputs. When the issue occurs, the NAI diagnostics indicate that the D/A module has an overcurrent condition via query to the overcurrent status register and we observe that the D/A output channels 1-4 are always at 0V.
During power on, and while the board is configuring (booting), there may be spurious conditions where the D/A channel senses a ‘false’ overcurrent condition. The solution is to perform a status ‘check’ and “reset overload” as part of your initialization process [VME64C2_DA_ResetOverload() command].
This was originally reported on a 64C2 VME board with an F1 D/A module, where the legacy call was VME64C2_DA_ResetOverload(). On current platforms the equivalent is the naibrd function naibrd_DA_ResetOverload(); see the DA Module Getting Started Guide for the recommended initialization sequence.