Siemens SG-6048-01 manual Setting Up the Converter

2 Setting Up the Converter

2 Setting Up the Converter

2.1Overview

Before connecting the converter to your system, understand the connectors, LEDs and switches. This section describes each of the following features according to their functions:

•four RS-485 communications ports

•one RS-232 communications port

•power module

•three configuration switches for communications

•manual and automatic operating modes

2.2RS-485 Communications Ports

The Isolated Multi-Drop converter is equipped with four RS-485 ports located on the converter’s front panel, as illustrated in Figure 2.1

			RS-485 receptacles
RS485		RS485		RS485		RS485
+	_	+	_	+	_	+	_

Figure 2.1 Connectors on Front Panel

Each port allows you to connect as many as 32 field devices on a single RS-485 communications cable; however, your application software may limit the number of devices your system can accommodate. Each port has Data(+) and Data(-) terminals and a ground terminal for the cable shield.

For diagnostics, each port is equipped with a yellow transmit (Tx) LED and a green receive (Rx) LED, located on top of the device. The Tx LEDs blink during the transmission of data, which occurs on all ports simultaneously; only one Rx LED blinks when data is received. The LEDs are illustrated in Figure 2.2

Figure 2.2 Communications LEDs on the Top Panel

2.3RS-232 Communications Port

The converter is equipped with one RS-232 communications port located on the rear panel, as illustrated in Figure 2.4. This port lets you connect the converter to a PC for desktop operation, or to a short-haul or dial-up modem for remote operation.

2.4Power Module

The interface of the converter’s power module is located on the rear panel, as illustrated in Figure 2.4. The power module includes an ON/OFF switch, an indicating power (PWR) LED, a 120 VAC power input, and a 15 VDC power output. The 15 VDC output is used to provide power to Static Trip IIITM trip units and SAMMSTM motor control and protection relays during testing. The filtered input next to the power switch is for providing line power to the converter. The power switch turns the converter on and off, and the PWR LED illuminates when the converter is turned on.

2.5Configuration Switches

On the rear panel are the converter’s three configuration switches, collectively labeled “TX CONTROL”. Set these switches before operating the converter. Refer to Figure 2.4 for the location of these switches. The two switches, labeled DCD/RTS and MAN/AUTO, and one thumbwheel switch, labeled BAUD are described below. This section describes the uses of each configuration switch in more detail.

2.5.1TX CONTROL Switches

The MAN/AUTO switch places the Isolated Multi-Drop converter in either manual or automatic operating mode, both of which are described below. Your application software determines which mode you should use.

The DCD/RTS switch is set according to the method of data transmission for your configuration. Set the switch to DCD for the Data Carrier Detect (DCD) circuit (pin 8, RS-232 cable) to send a message to the PC when a proper carrier signal is received. Set the switch to RTS for the Request To Send (RTS) circuit (pin 4, RS-232 cable) to send a message to the converter requesting permission to send data on the Tx Data circuit (pin 2, RS-232 cable). Figure 2.3 shows the switches set to DCD and AUTO.

Figure 2.3 Tx Control Switches

2 Siemens Energy & Automation, Inc.