Rockwell Automation 2708-DH5B2L_DH5B4L Attended Workstation - Manual (Page 23)

Chapter 2
Installing a Network
2–10
1. At the LAST workstation in the network, place the workstations into the
menu setup mode (see Appendix B).
a. Press the left arrow key (<) until the Diagnostic menu statement
appears in the display.
b. Press the ENTER key and then depress the left arrow key (<) until
RS-485 – BLK-Rx is shown on the display.
c. Press the ENTER key and the following should appear:
Rx = 00000 ERRS = 00
000
If the counters are not zero, press EXIT, then press ENTER, and they
should be set to zero.
d. Repeat steps a, b, and c for all workstations, except the Master
workstation.
2. At the Master workstation enter the Diagnostic menu and press the left
arrow key (<) until RS-485 – BLK-Tx is shown on the display.
a. Press ENTER and the display should show the following,
momentarily:
Tx = 00000 ERRS = 00
000
After the counters appear, the Tx counter will begin incrementing to
represent the number of blocks being transmitted over the network to all
workstations.
b. An observation of the display of the workstations placed in receive
will show the Rx counter changing accordingly as the transmitted
network blocks are received.
c. After a reasonable testing interval, press the EXIT key on the
Master workstation, thus suspending the network block test.
d. Examine each workstation to see that the Rx block count is the
same. It should be the same at all workstations (It is possible to be
off by one or two counts.) Also, inspect to see that ERRS count is
zero or less than three. Either a missing block count or high error
count indicates a bad network connection or a faulty workstation.
Exchanging the workstation will determine which is the case.
e. For additional confidence, perform step 1 at the Master workstation
location and step 2 at the last location. Step 1 may be repeated at all
other workstations. The changing of block transmission locations
verifies communications in the opposite direction.
f. Press EXIT three times on each workstation.
3. Always use retaining screws for all DB-9 connectors. Connect the RS-232
(or RS-422) cable to the host computer.
Testing the Network for
Data Transmission