Hitachi EH-150 Series, Applications Manual

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Chapter 6 Communication mode
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6.5.2 Performance
There are two communication processing for EH-SIO in CPU module. One is for port1, and the other one is for
port2. These communication processing handle only the request for 1 port at 1 time. This means in case of the
Hi-Protocol mode usage, the response time will be longer according to the increasing number of EH-SIO, because
of the several EH-SIO processing should be done by CPU module sequentially.
The rough response time of Hi-Protocol mode is shown in below. The values in this figure are not maximum value
but just reference.
Figure 6.56 Performance (Transmission control procedure 1)
Figure 6.57 Performance (Transmission control procedure 2)
Reference :
When using several EH-SIOs with Hi-Protocol mode, it is recommended to balance using both port numbers.
EH-SIO has two ports (Port1 and Port2). To get better performance using Hi-Protocol, the number of Port1 and
Port2 should be same. For example, mounting two EH-SIO modules on base rack and one Hi-Protocol mode is used
each EH-SIO, using Port1 of one EH-SIO and using Port2 of the other EH-SIO is recommended to get better
performance.
360 ms
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(*) Task Code :A4
60 points monitoring
HOST
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360 ms
(*) (*) Task Code :A4
60 points monitoring