Grass Valley VM 3000 System Controllers v.7.4 - Manual (Page 58)

Introduction
1−20 VM 3000 Installation and Operating Manual
— Each instance of the ASCII protocol counts as eight devices.
— Each instance of serial machine control (Sony machine, Ampex machine, etc.) counts as eight devices.
— Each instance of ESswitch counts as follows:
S If the switch rate is less than one switch per second sustained past five seconds, that instance counts as
twenty devices.
S If the switch rate is greater than one switch per second sustained past five seconds, that instance counts
as eighty devices.
Calculating Loading
— A maximum of eight devices may be assigned to an addressable controller port.
— Only one Sony VTR can be connected per port. Only one Ampex VTR can be connected per port. For ESbus
VTRs, one machine per port is recommended; this insures that the best possible response is realized.
— In order to calculate loading and quantity of processors required, the following steps should be followed:
1. Sum all base and fixed loading factors in the system.
2. If the system wide sum of all base and fixed loading factors is less than 160, this system is considered a “light-
ly” loaded system and a base multiplier of 1.0 should be used in later calculations.
3. If the system wide sum of all base and fixed loading factors is greater than or equal to 160 but less than 320,
this system would be considered a “medium” loaded system and a base multiplier of 1.5 should be used in
later calculations.
4. If the system wide sum of all base and fixed loading factors is greater than or equal to 320, this system is
considered a “heavily” loaded system and a base multiplier of 2.0 should be used in later calculations.
5. Using the base multiplier specified above based upon the system wide sum of the base and fixed loading fac-
tors, distribute the devices throughout the system not exceeding the following maximum loading for the VM
3000 and SI 3000 processors:
S VM 3000 maximum loading: 100
S SI 3000 maximum loading: 160
Note: The base multiplier is based upon the sum of the device counts of all devices system wide, NOT upon the
devices on any single processor board. Therefore, if the sum of the device counts is 400 system wide, you must
use a base multiplier of 2.0 when configuring the system. You can not merely sum the devices connected to each
individual processor using a base multiplier of 1.0 and keep this sum under the specified maximum loading.
Example
A system is to contain the following: