Data Communications with the Watlow Series 988 Family
Hardware and Wiring, Chapter 2
2.1
Hardware
Chapter 2 Hardware and Wiring
NOTE:
This manual applies
only to controllers
with the data
communications
option (9___-____-
_R__ or 9___-____-
_S__ or 9___-____-
_U__). Please use it
in conjunction with
the user's manuals.
Serial Hardware Interfaces
The Series 981-984, 986-989 and 996-999 controllers are factory-configured to
function in a broad variety of applications. The specifics of each controller's con-
figuration is encoded in its model number. Depending on your unit's model number,
you have one of two hardware interfaces:
1) RS-232 (9___-____-_R__) provides one-on-one communication with a maxi-
mum network length of 50 feet connecting one controller to one computer.
2) EIA-485 (9___-____-_S__) provides a "multidrop" or multiple-device network
with up to 32 addresses with a 4,000-foot network length limit. RS-422 pro-
vides a multidrop network for up to ten devices with a 4,000-foot network
length limit. To select the multidrop interface, enter the Setup Menu
[`SEt]
. Use the up-arrow or down-arrow key to advance to the Communica-
tions Menu
[COM]
. Press the MODE key until the interface prompt
[IntF]
appears. Select either 485 or 422. (Controllers equipped with the RS-232
interface do not require an interface selection.)
3) RS-232/EIA-485 (9___-____-_U__) If your controller is supplied with a "U"
board, you can select via the comms menu either EIA-232 or EIA-485 opera-
tion. The
[IntF]
parameter is defaulted to EIA-232. To select the multidrop
interface, enter the Setup Menu
[`SEt]
. Use the up-arrow or down-arrow key
to advance to the Communications Menu
[COM]
. Press the MODE key until
the interface prompt
[IntF]
appears.
Your Computer's Serial Interface
You can connect a data communication-equipped Series 981-984, 986-989 or 996-
999 to any computer with an RS-422, RS-232 or EIA-485 serial interface. A per-
sonal computer with an RS-232 serial output card, for instance, can talk to a single
RS-232 equipped controller.
For a multiple-controller network with one personal computer, you'll need a con-
verter to act as a bus, or multiple connection point.
For data communications serial interface converters for EIA-232 (RS-232), we
recommend either of these two suppliers:
• DATAFORTH Corp. (formerly supplied by Burr-Brown):
3331 E. Hemisphere Loop, Tuscon, AZ 85706
Tel: 1-800-444-7644, or (520) 741-1404 or Fax: (520) 741-0762
For EIA-422 (RA-422), part number: LDM 422
with a power supply and the correct 25 pin connector for your computer.
For EIA-485 (RS-485), part number: LDM 485
with a power supply and the correct 25 pin connector for your computer.
• B & B Electronics Manufacturing Company
707 Dayton Road, PO Box 1040, Ottawa, IL 61350
Tel: (815) 433-5100 or Fax: (815) 434-7094 or Web: http://www.bb-elec.com
For EIA-422/ EIA-485 (RS-422/ RS-485), part number: 485OIC
with a power supply and the correct 25 pin connector for your computer.
