Emerson MSM400 Computer Monitor User Manual


 
IP258
51
HAND HELD COMMUNICATOR REGISTERS
D9.0 SAFE, WORKING, OFFLINE, DEFAULT, Registers
Introduction to Registers
From the FUNCTION screen, whilst interrogating an MSM400 control unit, there is a selection titled
“BACKUP”. This allows the data now stored in the WORKING register (i.e. the MSM400 control unit
data) to be transferred to a separate secure memory, to either retain it while making changes to the
MSM400 control unit (i.e. as a “revert to the original program” insurance data store) or to save it in
memory so that it can be copied or consulted back in the office. The registers available are
WORKING REGISTER
This is literally the work sheet where all work is done – all changes made to the parameters on the
SMART Communicator keyboard are made to the data in the WORKING Register. While the
Communicator is attached across the 4-20mA loop, the WORKING register is exactly the same as the
MSM400 control unit memory, so all changes made to the WORKING register are also made to the
control unit itself. The MSM400 control unit memory and the WORKING register in the SMART
Communicator are identical. If communication between the two units fails, then changes attempted
in the WORKING register will be rejected.
Note : The SMART Communicator can be unaware of changes to the MSM400 control unit memory
made by (a) a Primary Master (such as Mobrey H-View) also attached to this control unit loop, and (b)
the local zero and span on the MSM400.
The data existing in the WORKING register is overwritten (and therefore lost) when new data is
loaded from another register, or when the SMART communicator is reconnected to an MSM400 loop,
because the start up routine will load this new MSM400 memory into the WORKING register. To
save any data that has been entered in an “Off-loop” state (i.e. back in the office) the data must be
held in the OFFLINE register (see below).
It is recommended that the data in the WORKING register is transferred OFFLINE before disconnection
of the SMART communicator from the loop, if it is likely to be needed for reference back in the office.
However, the data in the WORKING register is retained in the Psion memory after this disconnection,
and can still be interrogated until overwritten by new data.
SAFE REGISTER
The SAFE Register is literally a register where the current MSM400 calibration data can be stored and
kept SAFE, while changes are made on the WORKING register and the SMART Communicator is
attached to the loop. If these WORKING register changes then prove ineffective or not required, the
SAFE register data can be recalled into the WORKING register (and therefore to the MSM400 control
unit) to reset all the MSM400 parameters to their original values – i.e. the values in the control unit
when the last “Backup” operation transferring the data to the SAFE register was carried out. The data
in the SAFE register can only be loaded into the WORKING REGISTER when the communicator is
attached to the same MSM400 control unit that was the source of the data – i.e. the control unit with
the same unique identifier (D08). It is not possible to transfer programmes between instruments
using the SAFE register.
The SAFE register is retained even when the Communicator is disconnected from the loop, powered
down, and then reconnected to another loop, collecting new data in the WORKING register. It is not
accessible until the correct control unit loop is interrogated, so that the check on the D08 Unique
Identifier has been satisfied.
OFF-LINE REGISTER
This is the register used for transfer of programmes between one unit and the next, or from a
programme developed on the SMART Communicator at the office desk, stored OFF-LINE and then
down loaded into an MSM400 control unit on the plant later. Such data transfer is achieved by
connecting the SMART Communicator across the relevant MSM400 loop, loading the WORKING
register with the current MSM400 program (see below) then transferring the OFF-LINE stored data
into the WORKING register – this overwrites the previous programme in the MSM400 (both the
control unit memory and the WORKING Register).