I am using Intel's Voltage Rail Test Tool (VRTT) along with the Power Delivery Tool (PDT) software to test certain power rails on a motherboard. I've made it through static loadline testing in each of the Power States and am now to transient responses. I'm only able to acquire the transient repsonse measurements that occur within one PS mode. The testing that is not working requires the VRTT to test the transient response of the rails in question while switching from PS1 to PS0 over and over. This test is also required from PS2 to PS0 over and over. The issue is that the VRTT is not switching PS modes, and the PDT always reads 255 for the PS mode that it's in (it should only read 0-3). I've the Power Status Indicator (PSI#) signal and the Command Sync Output (CSO#) signal being monitored on my oscilloscope. Neither of these signals are asserting when they should be. If anyone has any knowlege or experience with the VRTT or any ideas at all please give me a shout out.