Micromod Micro-DCI: 53MC5000 MicroLink - Manual (Page 24)

8.2.1 PERFORMANCE TUNING
Three additional parameters are used to tune the operation of the gateway.
1. Set DATALINK DELAY INDEX (B289). Normally the default value of 0 is sufficient.
This value represents time in 10 ms increments and is only effective when the gateway op-
erates in Datalink interrogator mode (L260 = 1). For Datalink networks with SCADA adapt-
ers, this value should be set to accommodate RTS-CTS delays of transmitted and received
messages, as well as the data rate of the SCADA adapter RS232 port. (See IB 53SU5000,
Section 2, for SCADA time-out calculation procedures.)
2. Set MICROLINK RETRY DISABLE (L262) to 1 to deactivate MicroLink gateway message
retries. This value should normally be set to 0 when the gateway functions in Datalink re-
sponder mode. It should also be set to 0 if the gateway functions in Datalink interrogator
mode and only one or two MicroLink SUPERVISOR-PC units are generating all of the mes-
sages; otherwise, it should be set to 1.
3. Set AUTO CONNECT DISABLE (L263) to 1 to deactivate automatic updating of the
Datalink Node List (B608-B629) when the gateway is set up in Datalink interrogator mode.
This parameter has no affect when the 53MC5000 PCS is configured in Datalink responder
mode.
8.3 ACCESSING DATALINK INSTRUMENTS FROM MICROLINK NODES
8.3.1 SETTING MICROLINK SUPERVISOR-PC UNIT PARAMETERS
Prerequisites are SUPERVISOR board firmware must be revision 4.3 (or higher) and the
53MC5000 PCS gateway functions as a Datalink interrogator gateway.
Two SUPERVISOR-PC unit parameters control MicroLink network operation: they are the Time De-
lays B04 through B07, and the Time Between Transactions value (ms) B08. For standard Mi-
croLink or Datalink activity the default value of zero for these parameters is sufficient to ensure
reliable communications. These parameters, however, must be modified to optimize communica-
tions when either Datalink network instruments are connected to the MicroLink network via a gate-
way, or when MicroLink network instruments are connected to a Datalink network via a gateway.
• Time Delays (B04-B07) control the response message timeout duration. The
timeout duration can only be incremented in 10 millisecond intervals (e.g., 1 = 10
ms, 2 = 20 ms, etc.). Each Time Delay parameter (B04-B07) affects 8 instruments
as follows:
B04 applies to communications with instruments 0-7.
B05 applies to communications with instruments 8-15.
B06 applies to communications with instruments 16-23.
B07 applies to communications with instruments 24-31.
For gateway operations, these values are other than 0 only if their corresponding in-
struments are accessed through the gateway. It should be noted that these parame-
ters are also set for SCADA systems causing them to have values set to other than
0 even though their corresponding instruments are not accessed through the gate-
way.
• Time Between Transactions (B08) controls the minimum back-to-back
transaction time of the MicroLink network.
Section 8. Configuring the 53MC5000 PCS as a Gateway
25