The AV-602 interface is used for connecting from one to four gas detectors (4-20mA). Every detector gets its own address. The interface is connected to the central control panel through the S-90 or the XP-95 protocol.
The interface responds on one up to four addresses on the addressable loop. The interface sends out analogue values that result from currents on the 4-20mA -I inputs for detectors JAV1-JAV4. The conversion of current at the -I input into analogue value occurs according to the following function:
Additionally, a function for calculating the half-hour average, meant for preventing false alarms, is built-in in the interface. This function replaces in its entirety the collective dependence, which is normally used for this purpose.
3. ELECTRICAL PROPERTIES
The interface is powered by the addressable loop and operates in a voltage range of 17 to 28V. Its operation requires also the presence of an additional power supply of 10 to 30V DC.
4. SETTING THE ADDRESS
The interface has a 7-pole miniature switch with which the address can be set from 1 to 126. Next to each pole of the switch is written its value. The address is set by placing the switches with appropriate values in position 1: The address is the sum of the values of all switches in position 1. For example, for an address value of 5 the switches with values 1 and 4 must be set into position 1. Additionally, you need to adjust how many addresses an interface should occupy. This number must match the number of connected detectors. The setting is done with JP1 and JP2 jumpers.
5. COMPATIBILITY WITH THE ZARJA AV-902 INTERFACE
The AV-602 interface replaces up to four AV-902 interfaces, which is why it should be parameterized in such a manner – like 1-4 AV-902 interfaces (depending on how many detectors are connected).
6. DETAILS OF THE COMMUNICATION PROTOCOL
The function of the bits in this case is as follows:
- Output bits are not used.
- The called address is used for addressing the addressable unit.
- The Interrupt bit is not used.
- The analogue value is used to transfer the value of the current at -I input.
- Input bits are not used.
- The unit type which the interface uses to communicate its type is factory preset to 0, 1, 0, (bit 2, bit 1 and bit 0).
- The returned address, with which the interface confirms its presence, is the same as the called address.
- The XP-95 bit, with which the interface communicates that it supports the XP-95 protocol. It is set to 1.
- The alarm bit is not used.
- Extended TIP of the unit (XP-95 protocol extension) is set to 0, 0 (bit 4 and bit 3).
- Extended analogue value (XP-95 protocol extension), in which the eighth bit (LSB) of analogue value is transmitted.
- Parity bit (XP-95 protocol extension) is used to detect faults during communication. It is governed so that the number of bits 1 is always even.
- Interrupt/Alarm address (XP-95 protocol extension) is not used.
7. SPECIAL FEATURES
- The interface responds on one up to four addresses. The first address equals the setting of the 7-pole miniature switch, while the rest are the addresses that follow the set address. The number of addresses the interfaces occupies is set with the JP1 and JP2 jumpers (NUMBER OF OCCUPIED ADDRESSES).
- For its operation, the interface needs an additional power supply, which must suit the connected detectors, powered by the interface.
- The interface has an integrated function for calculating the half-hour average. This feature can be disabled (for the purposes of testing detectors on-site) by inserting a JP3 jumper (CURRENT VALUE).
8. MECHANICAL CONSTRUCTION
There are two versions of the AV-602 interface:
- VERSION: The interface is built into the surface mounted junction box. It can only be used in dry areas.
- VERSION: The printed circuit of the interface is attached to the carrier for mounting on a DIN rail. This version is intended for installation in a larger housings (cabinets).
MECHANICAL DIMENSIONS AND WEIGHT:
- VERSION (surface mounted junction box): 192 X 152 X 80mm, 438g
- VERSION (mounting on the DIN rail): 122 X 90 X 30mm, 80g
|Voltage of the S-90 or the S-XP95 addressable loop||17 to 28V DC|
|Additional power supply voltage (+U)||10 to 30V DC|
|Detectors power supply voltage (+S)||Additional power supply voltage (+U) reduced by 1V|
|Current consumption from the addressable loop at 24V||2.2mA (not interface state dependent)|
|Current consumption of additional power supply at 24V||3.3mA + the consumption of the connected detectors|
|Maximum allowed total consumption of connected detectors||1A (protected by a low voltage fuse)|
|The measuring range of -I inputs||20mA|
|Relative error of flow measurement of||± 5%|
|Period of stabilization after connecting the voltage||500ms|
|Temperature range of operation||-20 °C to +70 °C|
|Humidity (without condensation)||0 to 95% relative humidity|