Experimental Physics and
Industrial Control System

Andy Foster <[email protected]> · Thu, 22 Feb 1996 10:10:16 +0000 (GMT)

Deb,

Thanks for your answer regarding the interaction of access security and
"dm". The Gemini Project certainly has a vested interest in what is
going to be implemented. Broadly speaking your suggestions for each 
scenario seemed fine, i.e.

FIELD_ACCESS	MONITOR	"dm" ACTION	CONTROLLER "dm" ACTION

Read_Only	No change from now.	Value displayed but I think
		Just display value.     there should always be some
					indication that this
					channel cannot be written to
					because of security. By always
					I mean not just when someone
					tries to write to it.

Read & Write	No change from now.	No change from now.

Write_Only	I don't imagine ever using this combination.

No Read		Box of a certain	Box of the same colour
or Write	colour appears saying:	appears saying:
		"Read Access Denied"    "Write Access Denied"

As far as colour (or color) rules are concerned, I haven't used these
very much, but one thought I had was assigning one colour specifically
for access problems. That way, it would be immediately obvious to the
user that the problem was one of access security. 

With dynamic graphics, I agree with Deb and believe it is not a good 
idea to just not have the graphic show up. 
I think there should always be something 
which explicitly says "Read Access Denied" or "Write Access Denied". 

Obviously, I realise that at the moment, you are trying to gather together
the "user requirements". But do you have a feel for how long it would
take to make these sort of changes to the code? 

Cheers,

Andy

===================================================================================
Andy Foster
Royal Greenwich Observatory	Tel:       44 (0)1223 374899 (direct)
Madingley Road			Fax:       44 (0)1223 374700
Cambridge			E-mail:    [email protected]
CB3 0HA				Home Page: http://www.ast.cam.ac.uk/~ajf
UK

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System