How much technology a project manager should know? Is it just enough to know what's happenning in the team? Or more in the level of Solution Architet? Again there are different perspectives and variations. Let's consider a practical scenario and we'll see how each person in different roles act.
Let's say there happend to be a production problem in the middle of the night (if you are in the pub drinking during that time, don't take the call :) ) (say around 2 am, I like this time because this is the time I get calls) and it is serious issue and needs immediate attention. The below are the possible things each role can do if they get a call.
Q. What a developer can do?
A. A developer can login to the server, check logs and spends time understading what could have happend. Once problem is understood, he/she can see if this problem can be fixed remotely (assuming at 2 am you're at home doing remote login). If problem cannot be fixed from home or brain not responding, he/she convinces user who called by telling them that they can only fix at office hours.
Q. What a senior developer can do?
A. Whatever a developer will do + he/she will think what could've caused the problem and how to fix it in terms of design. Also how to permanently eliminate this error in near future.
Q. What a solution architect can do?
A. Whatever a senior developer can do + he/she thinks of a mitigation strategy to eliminate this kind of errors in the midnight, and thinks about a plan and process on how to provide permanent solution to avoid this error and many other errors relavant to this error in terms of architecture etc.
Q. What a project manager can do?
A. He/She immediately calls any one from above 3.
This is what happens in most of the companies I've worked. A project manager's duty is go look after project in terms of cost, estimations (team lead help needed in this area), task allocation. And each person in team answerable to project manager.
I know a manager many years back. In order to explain problem and solution we applied to the problem, we needed to teach her programming language we used. For example, if there was a problem, say a NullPointerException, we added null check to fix it, if we say there was an exception and we added condition to avoid it, she used to ask us, what is exception? what is null? etc questions. Quite irritating, but she is a manager. So we gave her a Java crash course in 5 minutes to her and explained the issue in detail. Man, she learned so much technology in crash courses almost became solution architect theoritically.
Putting bias aside, a project manager should have 70% management skill and 30% technology skill. That's why I always like to work under Solution Architect's supervision rather than pure management type people.
I also don't like to interact with business users, the moment we try to explain why certain things cannot be done with certain technologies (like controlling their browser settings from our servers, weird!!) they stop the discussion complaining 'its too technical'.
Because of all these experiences, I decided to stick to technical career path eventhough I am getting PMP training offers at good discounted price. I prefer to manager servers rather than managing people. At least, servers will follow your orders!!
Finally, a joke I remember about managers. Here it is:
A man goes into a pet shop to buy a parrot. The shop owner points to three identical looking parrots on a perch and says, "the parrot on the left costs 500 dollars".
"Why does the parrot cost so much," asks the man.
The shop owner says, "well, the parrot knows how to use a computer".
The man then asks about the next parrot to be told that this one costs 1,000 dollars because it can do everything the other parrot can do plus it knows how to use the UNIX operating system.
Naturally, the increasingly startled man asks about the third parrot to be told that it costs 2,000 dollars.
Needless to say this begs the question, "What can it do?"
To which the shop owner replies, "to be honest I have never seen it do a thing, but the other two call him boss!"
(copied from http://www.workjoke.com/managers-jokes.html)