Table 5-46. State Truth Chart For Physical Input Forcing Function; Figure 5-51. Force Physical Output Example - ABB TPU2000 Technical Manual

Table 5-46. State Truth Chart for Physical Input Forcing Function

Bit Value
Change Mask Normal/Forced Mask
Register 41427
0
1
1
1
Note: X = Don't Care State
Once an Output is forced on or off, it must be " unforced" or returned to normal state for the point to resume
normal operation and reflect the state present at the physical Output terminals present at the rear of the relay. It
is important to emphasize that the forced states are stored in the TPU2000R's non-volatile RAM and will
remain forced until unforced by the operator. A point may be "unforced" via the front panel MMI, DOS
ECP, WinECP, or through the Modbus commands covered within this section.
A simple example shall illustrate the Force/Normal control sequence via the Modbus command operations.
Figures 5-51, 5-52, and 5-53 illustrate the word patterns which must be transmitted to the TPU2000R to complete
a Force On, Force Off and Return to Normal State Operation within the TPU2000R. As with the other control
functions, the registers may be sent down individually, in blocks of data transferred, or as one block of data
followed by an execute command as illustrated in Figures 5-51, 5-52, and 5-53.
STEP 1 -
Host sends following register contents
to initiate Force Physical Output 6 ON ( Assumed that default
password of all spaces is active).
41424 = 2020 hex (Password Hi)
41425 = 2020 hex (Password Lo)
41426 = 0
41427 = 0040 hex (Select Bit to Change)
41428 = 0040 hex ( Place Bit in Forced State).
41429 = 0040 hex ( Send State of Force = 1)
TPU2000/2000R Modbus/Modbus Plus Automation Guide
Bit Value
Register 41428
X
0
1
1
EXAMPLE 3 - Force Output 6 to a State of 1 and Then to a Force State of 0, and
Then to a Normal State.
(Reserved)
E C
Command
Sequence Through
Modbus Command 16
Preset Multiple Holding Registers
E C
The Relay Responds
over the network that
the command has been
accepted.

Figure 5-51. Force Physical Output Example

Bit Value
Forced State
Register 41429
X Normal - State follows Voltage at Term.
X Normal - State follows Voltage at Term.
0 Output Forced – State = OFF
1 Output Forced – State = ON
STEP 2 -
The host sends the register execute
command to the following address
with the following contents.
41423 = 0001 hex
Command
Sequence Through
Modbus Command 16
Preset Multiple Holding Registers
The relay forces the Input Status of Physical Output 6 to be a
value of 1 Forced. A Modbus response will be returned to the host
indicating that the command has been accepted.
Description
E C
E C
145