Bacharach MGS 400 User Manual

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Bacharach MGS 400 User Manual Manual pdf 21 page image

1100-2294 Rev 1 20The MGS-460 features a remote sensor, which allows users to detect the presence of gases ininaccessible locations. Standard RJ45 “Cat 5E STP” Ethernet cable up to 5 meters long(included) may be used with the remote sensor.1. Remove the bottom right M20 cable gland plug and gland cap, and carefully remove thegland rubber insert. (The rubber insert is split to allow it to be installed around theprovided RJ45 cable.)2. Slip the cable gland nut over one end of the terminated RJ45 cable.3. Apply the split rubber insert onto the cable so that it is between the gland nut and theend of the cable.4. Feed the RJ45 connector through a cable gland and into the enclosure, taking care tonot damage the PCB.5. Remove all excess cable from the housing before securing the cable gland. (Confirmthat the RJ45 cable is not binding or stressing the PCB terminal block.)6. Plug the RJ45 connector into the provided RJ45 socket.3.4.5 Connecting to MGS-408 Gas Detection ControllerFor wiring and configuration information, please refer to the manual which is included with theMGS-408 (P/N: 1100-2295). At the central control system, connect the shield of the wires to the earth ground of thecontroller (e.g., the chassis, the ground bus-bar, etc.). For 24 VDC installations, the input is protected. If the polarity is reversed, the instrumentwill not power-up. For 24 VAC installations in daisy-chain, the neutral polarity must be maintained for allinstruments.3.4.6 Modbus RTU RS-485 InterfaceFor the Modbus RS-485 network use a 16 to 24 AWG (0.2 to 1.5 mm2) 3-core, 2 twisted pair +ground, shielded cable with 120 Ω characteristic impedance. (Recommended: Belden 3106A orequivalent.)The Modbus address, baud rate, stop bit, parity and slave termination is configured through thesetup menu. No jumpers or hardware switch settings are required.Ensure that the communication parameters within the network, including the BuildingManagement System, are configured identically.To ensure optimal performance of the Modbus network, ensure the following guidelines areimplemented:● Instruments are configured in a single bus topology, connecting multiple buses in parallelor branching multiple units from the main bus, may introduce impedance mismatches,reflections and/or signal distortions.● Avoid long stubs when connecting instruments to the bus (stubs should be less than 1meter in length).