MEGGITTVM600Mk2 MPC4Mk2 + IOC4Mk2 machinery protection and condition monitoring module

Mathematical function:

• Dynamic or auxiliary channels – any sensors

• 1 mathematically calculated measurement (Sum, Subtraction, RMS Sum, RMS Subtraction, Min or Max).

Differential housing expansion:

• Dynamic or auxiliary channels – LVDT type sensors

• 1 quasi-static measurement (differential expansion (mathematical subtraction)).

Notes:

In general, dual-channel processing requires that both channels are configured for fixed-frequency data 

acquisition and use the same filter (frequency span) settings, such as cutoff frequencies, attenuation and 

slope. However, Mathematical function processing does allow different processing functions to be combined.

Alarm processing

Alarms : Alarm with configurable limits (severity levels), hysteresis and time 

delay per processed output (data extraction)

Time delay : Up to 60 s in steps of 100 ms

Hysteresis : Up to 20% of the alarm level (physical quantity)

Severity levels

• Machinery protection applications : Out of range+, Danger+, Alert+,

Normal,

Alert−, Danger−, Out of range−

• Basic condition monitoring 

applications

: Out of range+, Danger+, Alert+, Information+,

Normal,

Information−, Alert−, Danger−, Out of range−

Adaptive monitoring : Adaptive monitoring uses a control parameter provided by an 

auxiliary channel (typically speed) to multiply the configured alarm 

limits by multiple coefficients configured for different ranges of the 

control parameter.

Trip multiplier uses the DSI TM control signal to multiply the 

configured alarm limits by a single configurable coefficient. 

See Discrete signal interface (DSI) inputs on page 14.

Alarm combination

Logic functions : AND, OR and majority voting logic (1oo2, 2oo2 and 2oo3), with 

optional inversion of individual inputs

Level 1 (basic) logic functions

• Number : 32

• Number of inputs per logic function : 32

• Configurable inputs : Sensor OK checks, measurement alarms (such as Danger+, Alert+, 

Alert− and Danger−) and/or associated data quality indicators 

(status bits)

Level 2 (advanced) logic functions

• Number : 32

• Number of inputs per logic function : 32

• Configurable inputs : Outputs from level 1 (basic) logic functions.

Note: Level 1 (basic) and level 2 (advanced) logic functions can 

be combined to generate more complex logic function.

Alarm update rate (internal) : 100 ms max.

Note: This is the time required for the MPC4Mk2 + IOC4Mk2 module to 

detect and initiate an alarm, including output relay (RL1 to RL4) 

activation.

Discrete signal interface (DSI) inputs

Control signal

• Alarm bypass (AB) : A closed contact between the DSI AB and RET inputs inhibits the 

activation of alarms and relays on the MPC4Mk2 + IOC4Mk2 module.

Note: The common circuit-fault relay (FAULT) is activated when 

Alarm bypass (AB) is enabled.

• Alarm reset (AR) : A closed contact between the DSI AR and RET inputs resets (clears) 

the alarms and relays latched by the MPC4Mk2 + IOC4Mk2 module.

Note: The Alarm reset (AR) input is edge-sensitive and a high-to-low 

transition is required to activate the reset. The Alarm reset (AR) input 

should not be held low and must transition low-to-high before 

another reset (high-to-low) can activate the reset.

• Trip multiply (TM) : A closed contact between the DSI TM and RET inputs multiplies the 

configured alarm levels for the MPC4Mk2 + IOC4Mk2 module by a 

scale factor (software configurable)

Operating principle : Detection of an open circuit or a closed circuit on the input

Buffered outputs – dynamic channels

Number : 4

Type : Buffered outputs (buffered “raw” analog signal).

Buffered analog signals corresponding to dynamic channel input 

channels (CH1 to CH4) are available on BNC connectors on the 

MPC4Mk2 module (front of rack) and on the J2 screw-terminal 

connector on the IOC4Mk2 module (rear of rack).

See Connectors on page 21.

Frequency bandwidth : DC to 60 kHz

Output impedance : <5 Ω

Accuracy

• Amplitude : ± 0.1 dB up to 20 kHz.

± 3 dB from 20 to 60 kHz.

• Phase : <1° from 10 Hz to 2 kHz.

<15° from 2 to 20 kHz.

Transfer ratios

• Voltage input : 1 V/V

• Current input : 0.2 V/mA

Admissible load on output

• Resistance : ≥50 kΩ

• Capacitance : Able to drive up to 3 m of cable with a typical capacitance 

of 100 pF/m

• Impedance : >50 kΩ with a load capacitance <5 nF

Buffered outputs – auxiliary channels

Number : 2

Type : Buffered outputs (buffered “raw” analog signal or TTL-level signal).

Buffered analog signals corresponding to auxiliary input 

channels (AX1 and AX2) are available on BNC connectors on the 

MPC4Mk2 module (front of rack) and on the J2 connector on the 

IOC4Mk2 module (rear of rack).

See Connectors on page 21.

Note: When an auxiliary input is configured as a tachometer input, 

a buffered TTL-level signal corresponding to the auxiliary input 

channel (AX1 or AX2) is available on the J2 connector on the 

IOC4Mk2 module (rear of rack). When an auxiliary input is 

configured as a DC input, no digital TTL-level signal is available.

Frequency bandwidth : DC to 60 kHz

Output impedance

• Buffered TTL-level signal

(tachometer input)