Mtbm Values - Allen-Bradley A-B QUALITY DL20 Series User Manual

Appendix H
Parallel Input Converters
Installation
H–4
4. To insure that the DL20 message or variable queue does not overflow
resulting in lost messages/variables, determine the minimum time
between message (MTBM) triggers (see Table H.A). The MTBM is
critical for applications where variables are being updated fast. Minimum
Time Between Messages (MTBM) values listed below are based on a
scan rate of 28.
Table H.A
MTBM Values (Scan Rate = 28)
Parallel Input Converter
Series A, B, & C
Series A & B
Series C & Later
Use the following instructions to mount and connect the Parallel Input
Converter to the DL20. Instructions are provided for both the display
mounted and the panel mounted versions. The approximate mounting
dimensions are shown in Appendix D.
ATTENTION: Before installing the parallel input converter,
disconnect all power from the DL20.
!
Display Mounted Version (Catalog No. 2706–NG1)
1. Mount the converter to the back of the DL20 by positioning it directly
under parallel port terminals 11A through 22 (D9–D0, MS1, MS0, and
+5V DC out).
2. Fasten the converter to the display using the two captive #6–32 screws
(supplied). Tighten the two #6 screws to 10 in.–lbs.
3. Tighten terminal screws 11A through 22 on the DL20 for electrical
continuity.
Dataliner
One / Two Line
Four Line
Four Line
MTBM
MTBM = MDHT
360 ms
310 ms