Meriam M1500 Digital Pressure Transmitter - Manual (Page 13)

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M1500 An M1500 An M1500 An M1500 Analog alog alog alog Models Models Models Models
Analog units are set up in the field using the supplied M1500 Meriam Setup Utility and a USB type A to USB type
mini-B cable. Power is provide over the USB cable for setup operations. The LED on the base of the transmitter will
blink red when only the USB cable is connected. The Meriam Setup Utility software supports pressure zero,
configuration of the output type and output span, plus selection of engineering units, damp rate and other parameters
(see the Firmware Features section of this manual for more details). Load the software on a suitable PC and use
optional p/n Z9P273 USB cable to connect the PC to the M1500’s USB port. Set up the transmitter as desired using
the Meriam Setup Utility.
Current Output Current Output Current Output Current Output
The M1500’s 4-20 milliAmpere (mA) output can be used with 2-wire loop power or in a 4-wire configuration. 2-wire
power supplies should be 24-36 VDC (60 mA minimum).
The 4-wire loop power supply should be an isolated type
(floating ground), 24-36 VDC (60 mA minimum) and the external supply should be 12-36 VDC (60 mA minimum).
Minimum loop impedance is 50Ω. See the Wiring Diagrams section and connect as appropriate.
The NAMUR low/high saturation limits for 2-wire and 4-wire current mode is 20.5mA.
The 20mA value can be set over a 4:1 turndown of the transmitters URL.
For 4- wire commissioning always connect the external supply to the PWR and GND terminals
before connecting the isolated loop supply to LP+ and LP–.
Voltage Output Voltage Output Voltage Output Voltage Output
Voltage output is 0-5 V DC but can be configured using the Meriam Setup Utility for any output span (for example, a
1-5V span may be more convenient for some applications). The voltage output uses a 4-wire system and requires a
12-36 VDC (60 mA minimum) power supply. The M1500 will draw a maximum of 10 mA from the power supply. See
the Wiring Diagrams section for details. The M1500 Transmitter can drive an output load having an impedance of 10K
ohms or more in parallel with up to 1µF of capacitance.
The low/high saturation limits for voltage mode are 0.0V and 5.1V respectively.
The 5V DC value can be set over a 4:1 turndown of the transmitters URL.
Switch Switch Switch Switch Output Output Output Output
Two solid state, opto-coupler, polarity independent, SPST switches are included on Analog output models of the
M1500. The opto-couplers are low power, rated for 80V DC and 100 mA max. Their use is limited to 4-wire 4–20 mA
or 4-wire 0–5 VDC options only (not available for 2-wire 4-20 mA operation).
Wiring Detection Feature Wiring Detection Feature Wiring Detection Feature Wiring Detection Feature
The M1500 has a wiring detection feature that is active for the first five (5) minutes after power up. Complete the
output wiring within the 5 minute period for proper operation. If wiring is not completed in the allotted time, simply
cycle power to re-activate the wiring detection sequence.
2-wire 4-20mA wiring 2 green LED blinks
4-wire 0-5Voltage wiring 3 green LED blinks
4-wire 4-20mA wiring 4 green LED blinks
If a fault condition occurs after the initial 5 minute period (e.g. output wiring changed, voltage drops below minimum or
climbs above maximum specified value), the green LED blink sequence will change to a red sequence.
Analog Connector