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C HAPTER 4 _____________________________________________________________ COMMISSIONING
CHAPTER 4
COMMISSIONING
When the DMP248 transmitter leaves the factory, its measurement ranges and output signals have already been selected. The user can subsequently change the measurement units between metric and nonmetric and select and scale the output signals with software functions, see Chapter Selecting and scaling the analogue output quantities and
Appendix 1.
Security lock jumper
Before the settings can be changed, the user must first remove the security lock jumper in connector X15 (see F IGURE 4-1 ). The security lock jumper makes it impossible to change the transmitter settings by mistake. The jumper should be removed only for changing the settings and for calibration; the auto-calibration is active only with the jumper connected. When the security lock jumper is connected, some commands cannot be used (see Chapter Commands and security lock jumpers).
X15
CHANGE OF SETTINGS
DISABLED
F IGURE 4-1
OPENED COVER OF THE DMP248
Location of the security lock jumper.
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OPERATING MANUAL _______________________________________________________________
Selecting the analogue outputs
The DMP248 transmitter can be ordered ready with the current or voltage outputs required. If the outputs need to be changed, move the jumpers in connector X15 into positions as shown in F IGURE 4-2 .
CH1 CH2
CURRENT OUTPUTS
0 ... 20 / 4 ... 20 mA
CH1 CH2
VOLTAGE OUTPUTS
0 ... 5 V / 0 ... 10 V
CH1 CH2
VOLTAGE OUTPUTS
0 ... 1 V
CH1 CH2
CH1 0 ... 1 VOLTAGE OUTPUT
CH2 CURRENT OUTPUT
X15
OPENED COVER OF THE DMP248
F IGURE 4-2 Selecting the analogue outputs with jumpers.
The software also has to be informed which outputs are in use. This is done either through the serial interface or the menus on local display when in use. The serial command is AMODE and the display/keypad command
"Mode ð Analog outputs ð Mode"
(see Chapter 5 commands ) . If the outputs need to be scaled, see serial
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C HAPTER 4 _____________________________________________________________ COMMISSIONING command ASCL and the display command
"Mode ð Analog outputs ð Scale"
.
All jumpers are used only with the 0...1 V outputs. When other outputs are in use, the spare jumpers are kept in connector X55.
X55 spare jumpers
OPENED COVER OF THE DMP248
F IGURE 4-3 Spare jumpers
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OPERATING MANUAL _______________________________________________________________
Connecting the RS 232C serial bus
RX
GND
TX
NC
X6
OPENED COVER OF THE DMP248
F IGURE 4-4 Serial bus connections.
To connect a PC to the DMP248 transmitters via the RS 232C serial bus, one of the following cables is required. The type of cable depends on the terminal and the connector type.
TXD
PC
TERMINAL
D9S
D25S
6
8
2
5
3
7
20
7
8
4
6
2
5
3
D25P
3
7
2
RXD
RXD
RXD
TXD
TXD
TX
GND
RX
TX
GND
RX
DMP248
TX
GND
RX
F IGURE 4-5 Three connection examples.
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NOTE
When the serial bus has been connected between the PC and the transmitter, the PC is switched on. When using a PC, a terminal emulation programme (e.g. HyperTerminal, Procomm Plus, Datastorm or Windows terminal) is started.
The factory settings for data transfer are:
•
4800 baud
• even parity
•
7 data bits
•
1 stop bit
• full duplex
When the serial bus settings are changed, the transmitter has to be reset before the new settings become effective.
The processor does not allow the following combinations:
• no parity, 7 data bits, 1 stop bit: if this combination is given the
DMP248 programme will change the number of stop bits to 2.
• even or odd parity, 8 data bits, 2 stop bits: if this combination is given the programme changes the number of stop bits to 1.
Refer to the manuals of the PC and the terminal emulation programme when giving serial settings.
The RS 232C screw terminal cannot be used if an RS 485/422 serial module or a current loop module is used. See Appendices 3 and 4 on how to install and operate these modules.
In calibrating or changing the settings of the transmitter, it can be more convenient to use the connector X17, if connector X6 is already in use. This connector, however, transfers only RS 232C signals. If a
RS 485/422 serial port module or a current loop module has been installed, it has to be removed before communicating through the X17 connector.
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OPERATING MANUAL _______________________________________________________________
RX GND TX
X17
NOTE
F IGURE 4-6 Location and connections of connector X17.
Some PC computers can generate interferences to the measured humidity and temperature values if the transmitter and the PC are connected to different mains outlets. To minimize the possibility of these interferences, always use the same main outlet (same phase of the main electricity) for the PC and the power supply of DMP248. It is always preferable to use the connector X6 instead of the connector
X17 because it is more immune to interferences.
Reverting to factory settings of the serial port
If the serial port settings are not known, no commands can be given via the serial interface. The settings can be reverted to the factory settings by inserting a jumper in connector X16. The jumper must be inserted when the power is on!
X16
OPENED COVER OF THE DMP248
F IGURE 4-7 Forcing the serial port settings back to factory settings.
When the jumper is inserted the serial line factory settings become valid, but only temporarily. The transmitter must be given new settings; otherwise, the transmitter uses the old, unknown settings after power-up.
When the new settings have been given, the transmitter must be reset. The jumper must be removed before the
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After jumper insertion the transmitter is in STOP mode, ready to receive commands.
The same method is used when the transmitter is in POLL mode and the user has forgotten its address.
CAUTION Inserting a jumper in any other place in connector X16 voids the guarantee of the transmitter.
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