Emerson Process Management ControlWave EFM 3808 - Manual (Page 42)

1-26 / Introduction CI-ControlWave EFM
1.5.5 Communications
A ControlWave EFM can be configured as a Master or Slave node on either a MODBUS
network or a BSAP network. Up to three communication ports are contained on the
ControlWave EFM CPU Module and are designated as follows:
CPU Module:
COM1 - Port 1: CPU Bd. J3, PC/AT 9-Pin Male D-Sub - RS-232
COM2 - Port 2: CPU Bd. J4, PC/AT 9-Pin Male D-Sub - RS-232
COM3 - Port 3: CPU Bd. J5, PC/AT 9-Pin Male D-Sub - RS-485 - Configured by SW3
A ControlWave EFM can support up to two optional Expansion Communications Modules,
which can reside in slots 3 and 4 (ONLY), in lieu of I/O Modules. Each Expansion
Communications Module contains two serial communications ports (one RS-232 and one
RS-485), an optional built-in spread spectrum modem (radio) and an optional built-in 56KB
PL/PSTN modem that are designated as follows:
Expansion Communications Modules:
COM4, COM5, COM6 & COM7 on first ECOM Bd., assigned to Base Chassis Slot #3
COM8, COM9, COM10 and COM11 on second ECOM Bd., assigned to Base Chassis Slot #4
COM4/8 - Port 1: ECOM Bd. J1, PC/AT 9-Pin Male D-Sub - Both RS-232
COM5/9 - Port 2: ECOM Bd. J2, PC/AT 9-Pin Male D-Sub - Both RS-485 - Configured by
SW1 on ECOM Board
COM6/10 - Port 3: ECOM Bd. Piggy-back Radio Module (FreeWave or MDS TransNet
Spread Spectrum Modem) Antenna connector provided
COM7/11 - Port 4: ECOM Bd. Piggy-back Modem Module (Multitech 56KB PL/PSTN
Modem) RJ-11 connector provided
Note: These RS-485 Ports are optionally available with 500Vdc isolation.
Communication Ports COM1, COM2, COM3, COM4, COM5, COM8 and COM9 support
serial asynchronous operation. Communication Ports COM1, COM2, COM4 and COM5
support RS-232 while COM3, COM5 and COM9 support RS-485 operation. Communication
Ports COM4/8, COM5/9, COM6/10 and COM7/11 reside on optional Expansion
Communications Modules (ECOM1/2). ECOM1 must reside in Base Chassis Backplane Slot
#3 while ECOM2 must reside in Base Chassis Backplane Slot #4. ECOM Modules have one
RS-232 Port and one RS-485 Port. Additionally, an ECOM Module may optionally contain a
56Kbaud PSTN Modem and/or a Spread Spectrum Modem (Radio). Any non-Ethernet
communication ports can be configured for local communications, i.e., connected to a PC
loaded with ControlWave Designer and OpenBSI software.
RS-232 Ports
An RS-232 interface supports Point to Point, half-duplex and full-duplex communications
(20 feet maximum, using data quality cable). Half-duplex communications supported by the
ControlWave EFM utilize MODBUS or BSAP protocol, while full-duplex is supported by
the Point to Point (PPP) protocol. ControlWave EFM RS-232 ports utilize the “null
modem” cable (Figure 2-12A) to interconnect with other devices such as a PC, printer,
another ControlWave EFM or other ControlWave series unit when the ControlWave
EFM is communicating using the full-duplex PPP protocol.
RS-485 Ports
ControlWave EFM can use an RS-485 communication port for local network com-
munications to multiple nodes up to 4000 feet away. Essentially, the master and the first