It all depends on device construction, whether you have hot plug options, whether the device has exposed metal connections to electronic internals and possible ESD events, or whether your primary concern is about FCC EMI restrictions. Some details of trade-offs can be found here.
The controversial "recommendations" come from the uncertainty under which condition the particular device will be used. USB is generally a "modular" system, so when things from different manufacturers come into a system, they don't know apriori how their device will be used, and provide minimal coupling between shield and signal ground. If you are designing an integrated system, my opinion is not to connect the shield with signal ground in intermediate hubs, and only couple the shield to signal ground at the battery power joint. Typically the coupling network has unpopulated footprints, and the components are selected/adjusted based on field/certification tests results.
Best Practice
Firstly (as a bit of a cop out) personally, in designs I always ground through a 0R resistor so that the decision can be changed. This goes for pretty much any shield (Ethernet, USB etc)
The main problem that can arise is when the shield is grounded at either end, and the two ends don't agree on what 0V is. This can cause damage to either end, by currents flowing where they shouldn't (if the shield path is 0.2ohms, and the voltage difference 1V, that's 5A going where it shouldn't)
You might think why would this ever happen? But think of the situation where a laptop is connected to a piece of mains powered equipment over USB. The laptop could be on battery only (no true earth reference), but the equipment is connected to mains and thus may have a true 0V earth reference.
So the solution is to connect at only one end, but have some agreement on which end.
Generally, a USB host device will be expected to provide the power and the slave device is quite often entirely bus powered and has no connections to anything else in the outside world (think USB memory stick, WiFi dongle etc). In general, the USB host should connect the shield to ground (and earth, if possible). This is why the host side is typically expected to tie the shield to ground or earth.
The fact that there are so many conflicting comments from people and different experiences shows clearly that it is far from safe to assume this is always adhered to, so as I mentioned firstly - add the option to change it easily.
In This Situation
After discussing this in a chat, the proposed solution is different. Since this is a question about ESD, it's messy and complicated and involves many aspects of the design (electrical, mechanical, system). The chat is available for all to see, but there important bits:
- This datalogger has no other connections, apart from the USB connection to a PC/laptop
- The datalogger has a metal chassis, that is bonded to the PCB board ground.
- When the USB shield is not directly connected to PCB board ground (for example connected by R||C or HiZ), the datalogger fails (loses memory contents).
- In the ESD test, the USB cable is not attached (or is floating at the other end).
- The OP is not the design author, and has very limited scope for making design changes to solve this problem.
I surmise the problem is most likely PCB layout related. The ESD surge is taking a path from the shield, past sensitive electronics and finally reaching the chassis. By directly connected the shield to the chassis with a wire, ESD surge path reaches the chassis without going near the PCB so avoids the problem.
In this situation, as the datalogger has no other connections to any other devices; the potential issues (pun intended) cannot occur. So I would suggest connecting the shield to the chassis. Either by a wire, or a more production friendly approach is an ESD gasket around the connector which is a spongey conductive material that gives a connection without manual soldering and doesn't permeantly attach the chassis to the board.
In a more ideal world, I would respin the board so the chassis is isolated from the PCB board ground and the chassis is connected to the shield. That means that its not possible for ESD surges to reach the sensitive electronics at all. Except if you poke the datapins on the USB connector for fun - in which case, ESD diodes on the datalines that give a path to chassis ground, not PCB board ground.
Best Answer
A 100nF capacitor might have this type of frequency response: -
As you mentioned, at 1 MHz the impedance is 1.6 ohms but if frequency rises you will reach a point where the capacitor self resonates and becomes inductive and, maybe the ferrite bead is intended to always restrain the net impedance to 200 ohm resistive no matter what frequency of signal might exist between shield and chip?
At much lower frequencies than 1 MHz the ferrite will behave like an inductor with fairly low losses and this may also be a feature desired by the designer.