Direct Access
To access count and measurement values in the set user area (USER STAT)
quickly from every program level, you can also use direct access with L PIW and
L PID. For L PIW use the module address plus offset 8 to offset 14 as the address;
for L PID use the module address plus offset 8 to offset 12 as the address.
You structure the area from module address + offset 8 in the parameter
assignment dialog boxes for the FM 350-2 using the menu command Edit >
Specify Channels.
Here you specify which value (count or measurement value) for which channel
(0 to 7) should be stored at which module address. Either the low word or the high
word of a value or both can be used.
The values are updated every 2 ms.
Consistency between the values when using direct access is only guaranteed if
you access the values as follows in accordance with the structure of this area:
Low word or high word of the value
L PIW
possible addresses = module address +8, +10, +12, +14
Both
L PID
possible addresses = module address +8, +12
我个人认为DBW44，DBW46，DBW48，DWB50对应的就是上面的PIWx+8,PIWx+10,PIWx+12,PIWx+14，这些要在“指定通道”中配置好。