Watlow Series 734 Data Communications - Manual (Page 3)

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WATLOW Series 733/734 How to Use Data Communications
How to Use Data Communications
with the Watlow Series 733/734
This manual is a supplement to the Series 733/734 Program and Service Manuals.
It is for controls with the data communications option. Use in conjunction with the
Program and Service manuals.
You Have One of Two Serial Hardware Interfaces
Depending on your unit's model number, you have one of two hardware
interfaces:
1)EIA/TIA-422 for a "multidrop" or (multiple device) network, up to ten devices
total; with 4000 ft. network length limit, or EIA/TIA-423 (EIA/TIA-232 compatible)
for one on one communication with a 50 ft. network length limit with a 733/734
(73xx-xxxx-xBxx) and a host computer. Selecting EIA/TIA-422 or EIA/TIA-423 is
user selectable via internal switches. See Page 7.
2)EIA/TIA-485 (73xx-xxxx-xDxx) also for a multidrop network, up to 32
addresses total, and with a 4000 ft. network length limit.
You Can Use One of Two Software Protocols
There are two protocols available to you. Depending on the type of network you
need, you must use the correct combination of interface and protocol.
We use ANSI X3.28 Protocol, based on ANSI X3.28 - 1976 Subcategories 2.2,
and A3, with the EIA/TIA-422 and EIA/TIA-485 interface to run a multiple device
network. We also use XON/XOFF Protocol, a simpler protocol, to run a two
device network with an EIA/TIA-423 interface. XON/XOFF will also work with the
EIA/TIA-422 and EIA/TIA-485 interface, but the network is limited to two devices
(one computer and a Series 733/734). XON/XOFF Protocol requires no responses
to messages like the ANSI X3.28 Protocol does. Likewise, ANSI X3.28 Protocol,
which provides a response to every message, will work with the EIA/TIA-423
interface. But again you are limited to one Series 733/734 and a host computer.
To select which protocol you are going to use, go into the Program menu and use
the MODE key to advance to the Prot prompt. Select either FULL, for ANSI X3.28
2.2 - A.3, or On for XON - XOFF.
If you are using ANSI X3.28 Protocol, choose an address number for the control
under the Addr prompt following the Prot prompt. This prompt will only appear if
Prot = FULL.
Communications Wiring
To connect your Series 733/734 to a computer, use the next three pages as a
reference. Your computer hardware manual will provide more detailed serial port
pin information. In the often noisy industrial environments, do not take noise
isolation lightly.
Data Comm
˜
NOTE:
This is expert user-
level material, and
requires previous
experience with data
comunications.