Chapter 3: Installation and Initial Setup
If you select RS-232 mode when you configure the Modbus Hardened Serial Server, you must connect the Modbus serial network to the Modbus Hardened Serial Server via a serial cable. The LES431A is a DTE. If the Modbus network is a DTE, use a null- modem (crossover) cable. If the Modbus network is a DCE, use a straight-through cable. DTE and DCE ports are complementary; the output signals on a DTE port are inputs to a DCE port, and output signals on a DCE port are inputs to a DTE port. The signal names match each other and connect pin-for-pin. Signal flow is in the direction of the arrows (see Table 3-1, below).
| | Table 3-1. DTE to DCE Connections. | |
DTE Device (Computer) DB9 | | DCE Device (Modem) DB9 |
Pin # RS-232 Signal Names | Signal Direction | Pin # | RS-232 Signal Names |
1 | Carrier Detect (CDA) | <---------------------------- | 1 | Carrier Detect (CD) |
2 | Receive Data (RX) | <---------------------------- | 2 | Receive Data (RX) |
3 | Transmit Data (TX) | ----------------------------> | 3 | Transmit Data (TX) |
4 | Data Terminal Ready (DTR) | ----------------------------> | 4 | Data Terminal Ready (DTR) |
5 | Signal Ground (SG) | ----------------------------- | 5 | Signal Ground (SG) |
6 | Data Set Ready (DSR) | <---------------------------- | 6 | Data Set Ready (DSR) |
7 | Request to Send (RTS) | ----------------------------> | 7 | Request to Send (RTS) |
8 | Clear to Send (CTS) | <---------------------------- | 8 | Clear to Send (CTS) |
9 | Ring Indicator (RI) | <---------------------------- | 9 | Ring Indicator (RI) |
Soldered to DB9 metal—Shield (FGND) | ----------------------------- | Soldered to DB9 metal—Shield (FGND) |
If you select RS-422 mode, RS-485 2-wire mode, or RS-485 4-wire mode when you configure the Modbus Hardened Serial Server, you must connect the Modbus network appropriately, via the 5-position terminal block.
NOTE: Refer to Appendix B for connector pinout information.
Network
Modbus
Hardened Serial
Server (LES431A)
RS-232 serial cable
RS-422/485 cable
PC
Figure 3-2. LES431A connections.
3.3 Connecting Modbus Hardened Serial Servers to a Network
When connecting a Modbus Hardened Serial Server equipped with a 10BASE-T/100BASE-TX network connection (RJ-45 connector) to an Ethernet network drop, use a standard unshielded twisted-pair cable. PCs configuring and/or communicating with the Modbus Hardened Serial Server are also connected to the network.
3.4 Modbus Hardened Serial Server Configuration Connections
The Modbus Hardened Serial Servers can be configured using three methods:
•Via the network using Modbus Hardened Serial Server Software.
•Via the network using a Web browser.
•Via a serial port using Modbus Hardened Serial Server Software (Console Mode).
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